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CV40 jet sizes

Started by 1340evo, February 18, 2021, 10:23:56 AM

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1340evo

My engines out right now, ".018 runout in the crank so I'm fixing it and doing everything whilst im in there, ballanced etc, so it will be like a new motor when I get it finished.
Anyway, the question is about the carb I have. I did raise this on here before but have been watching a few U tube vids whilst off this week on tuning the things for Harleys and think I've maybe been doing it a bit wrong.

I have a std 1340 and EV27 now. V&H shotguns and a open filter.. where I finished off last time was 48 / 190 to get it to pull through the range clean, bit it is running a tad rich (ok for running in). but on line, they say the slow running jet has more of an impact on the CV and saying that a 50-52 would be better and then maybe pull back on the main jet a bit, idle screw at 2.5 turns out.

Do people agree with this?. I've also lifter my needle a bit and all that but was getting a big flat spot mid range.

Please dont tell me drag pipes are crap, yes I now, but it beyond what you might expect with drags and the V&H are not that bad as the pipe starts out std size, then opens into the silencer paert so should be ok with reverb... thanks

thumper 823

I have a standard-issue answer.
This takes the guesswork right out!

AEM (and others)  make a wideband AFR ratio gauge.
If you are going to continue upgrades I highly recommend this tool  .
It reads on the fly and is POC install.
just weld in a bung...
You will no longer wonder what you should be doing and where to do it.
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Rising from the Ashes  UHIH

1340evo

February 18, 2021, 11:42:47 AM #2 Last Edit: February 18, 2021, 01:13:23 PM by 1340evo
may be an option.. ideal is 45 cm from the head or so it appears, but also looking at clip on tail pipe ones, any disadvantage with this type and saves making a hole?


These things are at least £200 over here but still cheaper than rolling roads etc...

xlfan

I have ran 1340's in that configuration, except open drag pipes for 25 years, with 46 slow jet, stock slide spring and non-raised needle.

I would stay away from 50-52 slow jets, I wouldn't even TRY them, if I wasn't sure they were for the CV, and not for its predecessor, the butterfly Keihin.

Scotty

Quote from: 1340evo on February 18, 2021, 10:23:56 AM
My engines out right now, ".018 runout in the crank so I'm fixing it and doing everything whilst im in there, ballanced etc, so it will be like a new motor when I get it finished.
Anyway, the question is about the carb I have. I did raise this on here before but have been watching a few U tube vids whilst off this week on tuning the things for Harleys and think I've maybe been doing it a bit wrong.

I have a std 1340 and EV27 now. V&H shotguns and a open filter.. where I finished off last time was 48 / 190 to get it to pull through the range clean, bit it is running a tad rich (ok for running in). but on line, they say the slow running jet has more of an impact on the CV and saying that a 50-52 would be better and then maybe pull back on the main jet a bit, idle screw at 2.5 turns out.

Do people agree with this?. I've also lifter my needle a bit and all that but was getting a big flat spot mid range.

Please dont tell me drag pipes are crap, yes I now, but it beyond what you might expect with drags and the V&H are not that bad as the pipe starts out std size, then opens into the silencer paert so should be ok with reverb... thanks

V&H Shotgun pipes are for show not for performance and that is a fact that has been proven many times over so don't kid yourself.
Evo 80", EV27 cams with a open air cleaner and open exhaust generally only require a 45 or 46 pilot and a 170-180 main and a needle that works.



Hossamania

Quote from: Scotty on February 18, 2021, 04:02:07 PM
Quote from: 1340evo on February 18, 2021, 10:23:56 AM
My engines out right now, ".018 runout in the crank so I'm fixing it and doing everything whilst im in there, ballanced etc, so it will be like a new motor when I get it finished.
Anyway, the question is about the carb I have. I did raise this on here before but have been watching a few U tube vids whilst off this week on tuning the things for Harleys and think I've maybe been doing it a bit wrong.

I have a std 1340 and EV27 now. V&H shotguns and a open filter.. where I finished off last time was 48 / 190 to get it to pull through the range clean, bit it is running a tad rich (ok for running in). but on line, they say the slow running jet has more of an impact on the CV and saying that a 50-52 would be better and then maybe pull back on the main jet a bit, idle screw at 2.5 turns out.

Do people agree with this?. I've also lifter my needle a bit and all that but was getting a big flat spot mid range.

Please dont tell me drag pipes are crap, yes I now, but it beyond what you might expect with drags and the V&H are not that bad as the pipe starts out std size, then opens into the silencer paert so should be ok with reverb... thanks

V&H Shotgun pipes are for show not for performance and that is a fact that has been proven many times over so don't kid yourself.
Evo 80", EV27 cams with a open air cleaner and open exhaust generally only require a 45 or 46 pilot and a 170-180 main and a needle that works.

Yup, that.
If the government gives you everything you want,
it can take away everything you have.

1340evo

Quote from: Scotty on February 18, 2021, 04:02:07 PM
Quote from: 1340evo on February 18, 2021, 10:23:56 AM
My engines out right now, ".018 runout in the crank so I'm fixing it and doing everything whilst im in there, ballanced etc, so it will be like a new motor when I get it finished.
Anyway, the question is about the carb I have. I did raise this on here before but have been watching a few U tube vids whilst off this week on tuning the things for Harleys and think I've maybe been doing it a bit wrong.

I have a std 1340 and EV27 now. V&H shotguns and a open filter.. where I finished off last time was 48 / 190 to get it to pull through the range clean, bit it is running a tad rich (ok for running in). but on line, they say the slow running jet has more of an impact on the CV and saying that a 50-52 would be better and then maybe pull back on the main jet a bit, idle screw at 2.5 turns out.

Do people agree with this?. I've also lifter my needle a bit and all that but was getting a big flat spot mid range.

Please dont tell me drag pipes are crap, yes I now, but it beyond what you might expect with drags and the V&H are not that bad as the pipe starts out std size, then opens into the silencer paert so should be ok with reverb... thanks

V&H Shotgun pipes are for show not for performance and that is a fact that has been proven many times over so don't kid yourself.
Evo 80", EV27 cams with a open air cleaner and open exhaust generally only require a 45 or 46 pilot and a 170-180 main and a needle that works.

I know on the pipes, but they are better than the full length SS ones I took off!

I'll try again when its all back together but before I was getting a very dead spot mid rpm, but the new cam may change things??

Hossamania

If the government gives you everything you want,
it can take away everything you have.

Don D

Quote from: xlfan on February 18, 2021, 02:06:37 PM
I have ran 1340's in that configuration, except open drag pipes for 25 years, with 46 slow jet, stock slide spring and non-raised needle.

I would stay away from 50-52 slow jets, I wouldn't even TRY them, if I wasn't sure they were for the CV, and not for its predecessor, the butterfly Keihin.

Best advise here.
KISS, simple button
Set the float and be sure the needle is stock. A 185 is a good start on a main jet. Idle mixture screw is set for best idle not any specific turns. An ignition box and timing changes will affect and help with overall tuning.
No kits, no special springs, no drilling is needed.

1340evo

what size idle jet you say?

1340evo

Quote from: xlfan on February 18, 2021, 02:06:37 PM
I have ran 1340's in that configuration, except open drag pipes for 25 years, with 46 slow jet, stock slide spring and non-raised needle.

I would stay away from 50-52 slow jets, I wouldn't even TRY them, if I wasn't sure they were for the CV, and not for its predecessor, the butterfly Keihin.

Thats a good point, Pacific Mike was on about it but it was a twin cam... is their CV differant?

1340evo

Quote from: Hossamania on February 19, 2021, 05:31:14 AM
What new cam?

I had the HD stoch FXR cam before, now changed on re-build to EV27

Don D

Quote from: 1340evo on February 19, 2021, 09:07:57 AM
what size idle jet you say?
Pilot 46 and it will weeze a little when cold off the enrichener. It should be able to be killed at idle by closing the idle mixture screw, if not pilot is too rich. A 48 will drink fuel and especially if they have the "fix" of the early pre-accelerator pump XL metering rod.

Hossamania

Same carb on Evo and Twin Cam.
If the government gives you everything you want,
it can take away everything you have.

Hossamania

You might also think about putting a 1/4" bolt in your pipes about 2 or 3 inches from the ends, think of a screwdriver being held at the end of your pipes across the opening. It will help break up the reversion that drag pipes cause.
Or something like this:

[attach=0]
If the government gives you everything you want,
it can take away everything you have.

1340evo

yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

this is the link to mike.  https://www.youtube.com/watch?v=cIN-apUaRi4

Do you rate this guy?   at 8mins 14 secs he's talking about a std bike at sea level taking a 50 to 52 slow running??

Scotty

Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

this is the link to mike.  https://www.youtube.com/watch?v=cIN-apUaRi4

Do you rate this guy?   at 8mins 14 secs he's talking about a std bike at sea level taking a 50 to 52 slow running??

I live at sea level and never used a 50 or a 52 in a cv not even on a 95" twin cam.
48 is to big for most twin cams and that is why the aftermarket made the 46 as genuine cv jets jump from 42 -> 45 -> 48 and 45 was a tad lean and 48 a lot rich.
I have no idea who he is or where he is but after watching that I would not ever let him near any of my carbs.

Hossamania

I run a hot 95" with a cv44 carb, and still use only a 46 pilot.
If the government gives you everything you want,
it can take away everything you have.

Hossamania

Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

If you use the baffles, no need for lollipop.
Without the baffles, you can run just a 1/4" across there, you don't need a lollipop. Mine is kind of fancy, you can weld a washer to a bolt and get the same effect.
I run mine turned wide open, not closed like the picture. That is a Thunderheader that used to have a reverse cone baffle, but it rotted out, hence the lollipop.
If the government gives you everything you want,
it can take away everything you have.

1340evo

Quote from: Hossamania on February 19, 2021, 12:01:14 PM
Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

If you use the baffles, no need for lollipop.
Without the baffles, you can run just a 1/4" across there, you don't need a lollipop. Mine is kind of fancy, you can weld a washer to a bolt and get the same effect.
I run mine turned wide open, not closed like the picture. That is a Thunderheader that used to have a reverse cone baffle, but it rotted out, hence the lollipop.

Do reverse cones work or just restrict your exhaust port from the head?

1340evo

Quote from: Scotty on February 19, 2021, 11:14:04 AM
Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

this is the link to mike.  https://www.youtube.com/watch?v=cIN-apUaRi4

Do you rate this guy?   at 8mins 14 secs he's talking about a std bike at sea level taking a 50 to 52 slow running??

I live at sea level and never used a 50 or a 52 in a cv not even on a 95" twin cam.
48 is to big for most twin cams and that is why the aftermarket made the 46 as genuine cv jets jump from 42 -> 45 -> 48 and 45 was a tad lean and 48 a lot rich.
I have no idea who he is or where he is but after watching that I would not ever let him near any of my carbs.

He's got a big following and engine build things he does is worth watching (if you can keep awake  :teeth: ), but yes, just shocked me when hes talking 52!
I'm going to put a better filter on and maybe go down a size on both jets then, see how we go

Scotty

Quote from: 1340evo on February 19, 2021, 12:32:56 PM
He's got a big following and engine build things he does is worth watching (if you can keep awake  :teeth: ), but yes, just shocked me when hes talking 52!
I'm going to put a better filter on and maybe go down a size on both jets then, see how we go

No thanks after watching that one..............to me he missed the obvious an intake leak and he masked it with a bigger jet which just points to me that he is a nobody hack using the internet for fame and fooling people like yourself. Not his problem if you damage your bike as he is not going accept responsibility.
I follow the moto believe nothing of what you hear and half of what you see and it has served me well over the years.

Hossamania

Quote from: 1340evo on February 19, 2021, 12:29:55 PM
Quote from: Hossamania on February 19, 2021, 12:01:14 PM
Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

If you use the baffles, no need for lollipop.
Without the baffles, you can run just a 1/4" across there, you don't need a lollipop. Mine is kind of fancy, you can weld a washer to a bolt and get the same effect.
I run mine turned wide open, not closed like the picture. That is a Thunderheader that used to have a reverse cone baffle, but it rotted out, hence the lollipop.

Do reverse cones work or just restrict your exhaust port from the head?

It works well on the Thunderheader, always a top horsepower performer.
If the government gives you everything you want,
it can take away everything you have.

Hossamania

Quote from: 1340evo on February 19, 2021, 12:32:56 PM
Quote from: Scotty on February 19, 2021, 11:14:04 AM
Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

this is the link to mike.  https://www.youtube.com/watch?v=cIN-apUaRi4

Do you rate this guy?   at 8mins 14 secs he's talking about a std bike at sea level taking a 50 to 52 slow running??

I live at sea level and never used a 50 or a 52 in a cv not even on a 95" twin cam.
48 is to big for most twin cams and that is why the aftermarket made the 46 as genuine cv jets jump from 42 -> 45 -> 48 and 45 was a tad lean and 48 a lot rich.
I have no idea who he is or where he is but after watching that I would not ever let him near any of my carbs.

He's got a big following and engine build things he does is worth watching (if you can keep awake  :teeth: ), but yes, just shocked me when hes talking 52!
I'm going to put a better filter on and maybe go down a size on both jets then, see how we go

On a 1340, I seriously doubt you need anything bigger than a 46, have a 45 on hand to try both. 180 main probably as big as you'd need as well, but again, have a 190 and maybe even a 170 on hand. Tuning is fun!
And check for vacuum leaks before you even start. All hoses, intake flanges, etc.
If the government gives you everything you want,
it can take away everything you have.

1340evo

Quote from: Hossamania on February 19, 2021, 01:49:44 PM
Quote from: 1340evo on February 19, 2021, 12:32:56 PM
Quote from: Scotty on February 19, 2021, 11:14:04 AM
Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

this is the link to mike.  https://www.youtube.com/watch?v=cIN-apUaRi4

Do you rate this guy?   at 8mins 14 secs he's talking about a std bike at sea level taking a 50 to 52 slow running??

I live at sea level and never used a 50 or a 52 in a cv not even on a 95" twin cam.
48 is to big for most twin cams and that is why the aftermarket made the 46 as genuine cv jets jump from 42 -> 45 -> 48 and 45 was a tad lean and 48 a lot rich.
I have no idea who he is or where he is but after watching that I would not ever let him near any of my carbs.

He's got a big following and engine build things he does is worth watching (if you can keep awake  :teeth: ), but yes, just shocked me when hes talking 52!
I'm going to put a better filter on and maybe go down a size on both jets then, see how we go

On a 1340, I seriously doubt you need anything bigger than a 46, have a 45 on hand to try both. 180 main probably as big as you'd need as well, but again, have a 190 and maybe even a 170 on hand. Tuning is fun!
And check for vacuum leaks before you even start. All hoses, intake flanges, etc.

yes, did all that before, but the only way I could get it to pull through the mid rpm drop was 48 / 190 but as I say, it's rich?
Cant do nothing now till its back together, but like the area it went from slow running to main jet, it would drop off a cliff... 48/190 did cure it... timing spot on, VOSE working fine etc??.. who knows till we are back up...

1340evo

Quote from: Hossamania on February 19, 2021, 01:45:58 PM
Quote from: 1340evo on February 19, 2021, 12:29:55 PM
Quote from: Hossamania on February 19, 2021, 12:01:14 PM
Quote from: 1340evo on February 19, 2021, 10:56:52 AM
yes, did try this on the old pipes, but maybe I didn't go big enough? The V&H have end baffles in, but do like them without better, may have another go with the lolipop things

If you use the baffles, no need for lollipop.
Without the baffles, you can run just a 1/4" across there, you don't need a lollipop. Mine is kind of fancy, you can weld a washer to a bolt and get the same effect.
I run mine turned wide open, not closed like the picture. That is a Thunderheader that used to have a reverse cone baffle, but it rotted out, hence the lollipop.

Do reverse cones work or just restrict your exhaust port from the head?

It works well on the Thunderheader, always a top horsepower performer.

May give them a go... see how they work, they must restrict your top end tho?

Hossamania

February 19, 2021, 03:05:21 PM #26 Last Edit: February 19, 2021, 03:11:01 PM by Hossamania
The reverse cone is a baffle that goes in the muffler body. I think you might be talking about torque cones that bolt in the flange at the head on the motor. Those work, kind of. The bolt works as well or better, in general, less restriction.
Don't get me wrong, I like drag pipes because they look good and are loud, but not ideal performers obviously. They are known for their soft low and midrange dip.
This is a reverse cone, not the same construction as the Thunderheader baffle, but same concept, bolts into the muffler body.
link
If the government gives you everything you want,
it can take away everything you have.

Scotty

Quote from: 1340evo on February 19, 2021, 02:43:19 PM
yes, did all that before, but the only way I could get it to pull through the mid rpm drop was 48 / 190 but as I say, it's rich?
Cant do nothing now till its back together, but like the area it went from slow running to main jet, it would drop off a cliff... 48/190 did cure it... timing spot on, VOSE working fine etc??.. who knows till we are back up...

Did you try any different needles? And that exhaust is going to have a big dip as well.

Hossamania

And now with a fresh motor, all tuning back to step one. Are you freshening up the heads?
If the government gives you everything you want,
it can take away everything you have.

1340evo

ok, wrong cones.... I did mean the head ones.

Yes, ive done the lot, heads flowed etc.

1340evo

Quote from: Scotty on February 19, 2021, 03:10:52 PM
Quote from: 1340evo on February 19, 2021, 02:43:19 PM
yes, did all that before, but the only way I could get it to pull through the mid rpm drop was 48 / 190 but as I say, it's rich?
Cant do nothing now till its back together, but like the area it went from slow running to main jet, it would drop off a cliff... 48/190 did cure it... timing spot on, VOSE working fine etc??.. who knows till we are back up...

Did you try any different needles? And that exhaust is going to have a big dip as well.

No i didn't , i lifted the existing one by a shim or two, but kept the FXR needle... I know they say Sporty needle is good.. 98 or something...

Scotty

Quote from: 1340evo on February 19, 2021, 03:35:26 PM
No i didn't , i lifted the existing one by a shim or two, but kept the FXR needle... I know they say Sporty needle is good.. 98 or something...

The Sportster one is ok it is the N65C
This is where a O2 meter comes in handy swapping needles because you would be amazed at the difference.
I run a N8EA at the moment and bike runs great but I used a O2 meter.
Pull your needle out and use a magnifying glass and read the number on it then you will know exactly what you have in there.

1340evo

Quote from: Scotty on February 19, 2021, 05:08:43 PM
Quote from: 1340evo on February 19, 2021, 03:35:26 PM
No i didn't , i lifted the existing one by a shim or two, but kept the FXR needle... I know they say Sporty needle is good.. 98 or something...

The Sportster one is ok it is the N65C
This is where a O2 meter comes in handy swapping needles because you would be amazed at the difference.
I run a N8EA at the moment and bike runs great but I used a O2 meter.
Pull your needle out and use a magnifying glass and read the number on it then you will know exactly what you have in there.

there are no marks on the needle, this is the small 0".028 washer I used. One thing I did see is the throttle stop is probably being used to control tickover as the idle screw as you can see is into the main airway and only 1 full turn out.
How do you set the throttle stop on these, is there a setting between the butterfly and body?

Don D

What people don't realize is back in the day the bikes were almost rich in the mid to main circuit as-is. The pilot was too small, lean. When a stage one was added the ugly truth became exaggerated. Using an AFR meter at steady state is fine but on acceleration the accelerator pump will have the reading go momentarily rich. The pipe is a bit of a problem, agreed.

1340evo

Quote from: HD Street Performance on February 20, 2021, 06:50:08 AM
What people don't realize is back in the day the bikes were almost rich in the mid to main circuit as-is. The pilot was too small, lean. When a stage one was added the ugly truth became exaggerated. Using an AFR meter at steady state is fine but on acceleration the accelerator pump will have the reading go momentarily rich. The pipe is a bit of a problem, agreed.

There does appear to be a call for bigger idle jets. so maybe 48 is worth keeping... and just drop back on the main jet a bit?
I do need it running on the idle jet thos and not the butterfly stop

Scotty

Quote from: HD Street Performance on February 20, 2021, 06:50:08 AM
What people don't realize is back in the day the bikes were almost rich in the mid to main circuit as-is. The pilot was too small, lean. When a stage one was added the ugly truth became exaggerated. Using an AFR meter at steady state is fine but on acceleration the accelerator pump will have the reading go momentarily rich. The pipe is a bit of a problem, agreed.

Yes the main jet was almost always to big and it was usually just the slow jet and the idle AFR which needed tweaking but HD also kept changing needles which also caused irritating transitions from idle circuit to needle. That is why swapping needles and seeing what happens is an eye opener.
The accelerator pump is something you just have to allow for and is well needed and still used in EFI bikes (accel / decel enrichment) which you can turn off to tune without. On the Mikuni you can also disable the accel pump but the CV is a little harder to do but can still be done as well if you know what you are doing.

Scotty

Quote from: 1340evo on February 20, 2021, 10:52:51 AM
There does appear to be a call for bigger idle jets. so maybe 48 is worth keeping... and just drop back on the main jet a bit?
I do need it running on the idle jet thos and not the butterfly stop

Yes and yours would have originally come with a 42 pilot jet so as you have already been told the 45 would be next and then the 48 which is generally to big which is why we drop back to the 46. I have a different cam to you and my idle circuit is rich with a 46 and 48 would drown it. My mates bike with EV27 .030 HG cleaned up and decked Evo heads runs perfect on a 45 and you want to put a 50 in at the beginning of this thread.
Maybe your carb is worn out, they don't last forever and do have a life span.
Is the butterfly jamming up on the bottom or is is just close? They only have a small gap.
Also if the number is no visible on the straight part of the needle at the top then it is not a genuine needle! It cannot be seen without a bright light and magnifying glass for 98% of the population.

1340evo

OK, here's the plan...
drop back to 46 pilot and 180 main (at least for running in).
What needle do I get if this one is a unknown so at least we start from a know position?.. do I shim the new one?
Also, is there a base setting for the butterfly gap? .001 Maybe?.. if i just crack open the butterfly and push / pull on the linkage I can maybe move the butterfly up and down .001 so guess thats okay

The carb itself looks quite new and nothing sticking.
The float closes off just above level position
There is no number on the needle
There is a burn on the plastic and diaphragm relative to the choke hole... but no holes


Scotty

Quote from: 1340evo on February 20, 2021, 12:25:47 PM
OK, here's the plan...
drop back to 46 pilot and 180 main (at least for running in).
What needle do I get if this one is a unknown so at least we start from a know position?.. do I shim the new one?
Also, is there a base setting for the butterfly gap? .001 Maybe?.. if i just crack open the butterfly and push / pull on the linkage I can maybe move the butterfly up and down .001 so guess thats okay

The carb itself looks quite new and nothing sticking.
The float closes off just above level position
There is no number on the needle
There is a burn on the plastic and diaphragm relative to the choke hole... but no holes

Read this and have a look around the site
https://cv-performance.com/harley-cv-carburetor-tuning-issues
They also sell a N65C needle and one they made themselves called a velocity needle - i have never used but it has had good reviews

1340evo

February 20, 2021, 01:34:41 PM #39 Last Edit: February 20, 2021, 01:49:00 PM by 1340evo
Quote from: Scotty on February 20, 2021, 01:22:09 PM
Quote from: 1340evo on February 20, 2021, 12:25:47 PM
OK, here's the plan...
drop back to 46 pilot and 180 main (at least for running in).
What needle do I get if this one is a unknown so at least we start from a know position?.. do I shim the new one?
Also, is there a base setting for the butterfly gap? .001 Maybe?.. if i just crack open the butterfly and push / pull on the linkage I can maybe move the butterfly up and down .001 so guess thats okay

The carb itself looks quite new and nothing sticking.
The float closes off just above level position
There is no number on the needle
There is a burn on the plastic and diaphragm relative to the choke hole... but no holes

Read this and have a look around the site
https://cv-performance.com/harley-cv-carburetor-tuning-issues
They also sell a N65C needle and one they made themselves called a velocity needle - i have never used but it has had good reviews

Did read that before.. all okay, I tested for leaks with easy start.
Its not setting off where I have the problem, its mid rang where without big jets, it bogged down and struggled to get through into the higher RPM.
Could it be down to the 0".018 runout on the crank and bad resinance at that point holding it back?
Think I'll order a stock emusion tube and a stock needle there again, I know my starting point.. or should I get the sporty needle??

Scotty

I would put a stock emulsion tube in regardless and a 46 pilot a 75-80 main and the velocity needle.
I would also put a rebuild kit through the carb and new boot and intake seals.

1340evo

Quote from: Scotty on February 20, 2021, 01:39:18 PM
I would put a stock emulsion tube in regardless and a 46 pilot a 75-80 main and the velocity needle.
I would also put a rebuild kit through the carb and new boot and intake seals.

would you go for the std needle?

Scotty

February 20, 2021, 02:13:22 PM #42 Last Edit: February 20, 2021, 02:21:57 PM by Scotty
Quote from: 1340evo on February 20, 2021, 01:50:01 PM
would you go for the std needle?

The one you have has no number and I doubt you can buy a std needle from a dealer anywhere as they getting hard to come by.
Harley seemed to change needles every year look at the attached chart and that is just Evo stuff.
[attach=1,msg1378837]
[attach=1,msg1378837]

1340evo

OK

N65C

Pilot 46

and new emulsion tube ordered...

Lets see what they look like against what I have when they arrive ;)

1340evo

February 21, 2021, 02:34:34 AM #44 Last Edit: February 21, 2021, 04:55:11 AM by 1340evo
Only other needle available was a n86E

type    A         D1       D2         D3         D4         D5         D6
N65c   2.266   0.108   0.0975   0.0900   0.0810   0.0700   0.0630
N86e   2.249   0.108   0.1000   0.0875   0.0775   0.0730   0.0685

diff     0.017    0      -0.0025  +0.0025 +0.0035 -0.0030 -0.0055

However,
The N86e is shorter, so the sizes (gap) will become bigger (needle smaller) sooner by about 6.8% between the two sizes.
corrected the N86e gives :-

type     A         D1       D2         D3         D4         D5         D6
N65c    2.266   0.108   0.0975   0.0900   0.0810   0.0700   0.0630
N86e    2.266   0.108   0.0990   0.0865   0.0765   0.0730   0.0685

diff       0         0        -0.001   +0.003    +0.005  -0.003   -0.005

So the N65c will start off a bit richer, get leaner mid range, then a bit richer top end

Is that right  :scratch:


1340evo

February 21, 2021, 06:05:26 AM #45 Last Edit: February 21, 2021, 10:07:34 AM by 1340evo
Does anyone know the base setting for the butterly at all? how far open it should be in the closed position?

Thanks...

1340evo

Quote from: thumper 823 on February 18, 2021, 11:10:19 AM
I have a standard-issue answer.
This takes the guesswork right out!

AEM (and others)  make a wideband AFR ratio gauge.
If you are going to continue upgrades I highly recommend this tool  .
It reads on the fly and is POC install.
just weld in a bung...
You will no longer wonder what you should be doing and where to do it.

ok, got a AEM-X serier meter. Which sensor are you using with it? if its the 18.5mm thread one, where on the pipe are you installing it to get the distance from the head (24" I think) and the right angle?... It's a big ol sensor or are you using smaller ones?

Don D

The closer you get the sensor to the head the more accurate it will be. There are specifications for mounting to be found on the net. They require a slight down angle as well.

1340evo

it says 24" from the head so it don't get too hot? but if it would work closer, it would be easier to mount... the sensor must block half the pipe off when inserted LOL

Don D

Use the sensor manufacturers instructions. The closer it gets to the head the less likely it is to get false information from atmospheric air and a mostly open exhaust. It needs to point down 10 degrees. From the DTT literature:

Select a convenient mounting location for the Bosch sensor. In general, the sensor should be mounted as close to the exhaust valve or exhaust manifold as practical. When choosing a mounting location, allow several inches clearance for the sensor wire harness. The wire harness must exit
straight out from the sensor

1340evo

Quote from: HD Street Performance on March 06, 2021, 06:44:48 AM

Select a convenient mounting location for the Bosch sensor. In general, the sensor should be mounted as close to the exhaust valve or exhaust manifold as practical. When choosing a mounting location, allow several inches clearance for the sensor wire harness. The wire harness must exit
straight out from the sensor


interesting... some info I was reading said 24". I've not actualy opened the box as yet as its at work and I'm at home. Will have a read Monday ;)

Don D

I can understand that advise as it relates to cars especially with a closed exhaust system

1340evo

Are you guy's using a 12mm sensor or 18mm?

Looking at a 18mm sensor, it will block off a lot of the exhaust....

But can you get 12mm wideband units?

JW113

24" on a bike exhaust is way too far back. Mine is maybe 7" from the exhaust port, and only because any closer there is no access. I have the Bosch sensor, 18mm, same as a spark plug.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

okay, just looks big for the pipe... would of thought most bike application would be the 12mm if they do wide band....

Burnout

Use a long bung when mounting an O2 in a header pipe so the sensor does not mess with flow.

If you put it in a larger pipe there is less of an issue, but in a runner you don't want the sensor blocking flow.
They don't call me Ironhead Rick just because I'm "hard headed"

1340evo

September 04, 2021, 11:29:34 AM #56 Last Edit: September 04, 2021, 01:24:20 PM by 1340evo
Okay, with the engine close to run in, I've just changed my jets.
It was kind of thumpy every time it fired so I'm thinking over fueling a tad. I was at 46 / 185 so I've dropped back to 45 / 180 and its so much better. picks up better and not as harsh. I've kept the sporty needle.
So next as I can open her up a bit now is to get the AFR meter on it and see how it looks.
Seat of pant tho, its much better at the lower jets :)  and the plugs are starting to look better (only 10 miles on them at the new settings)


1340evo

Well. Its got cold here in the UK and over the weekend it was 4 deg. I took the bike out and it kind of didn't go as well as I expected, like its running rich (does that add up?.. Lots of thick cold air now where as summer I guess its thinner and hotter?
It does pop on over-run with the V&H pipes but it coughed back through the carb a couple of times also, something its not done before.

wfolarry

How does it run with the choke on? That can give you some indication if it's rich/lean.

Deye76

"like its running rich (does that add up?.."

Cold air is denser than warm air generally creating a lean condition.
East Tenn.<br /> 2020 Lowrider S Touring, 2014 CVO RK,  1992 FXRP

1340evo

so the colder it get's, the leaner it gets?...  are you sure?

Don D

Every mild CV40 EVO I had back in the day would run well with a 45 pilot, up from stock 42.

Deye76

November 22, 2021, 10:26:37 AM #62 Last Edit: November 22, 2021, 10:48:28 AM by Deye76
Quote from: 1340evo on November 22, 2021, 07:58:24 AMso the colder it get's, the leaner it gets?...  are you sure?

Only things I'm sure of is taxes and death.
Google it, or ask a dyno tuner.

Your earlier post,............ "So next as I can open her up a bit now is to get the AFR meter on it and see how it looks."
What does your AFR gauge show?
The S&S on my FXR runs leaner when it's colder out, fuel consumption is 4 mpg better when it's 40 deg. F.
East Tenn.<br /> 2020 Lowrider S Touring, 2014 CVO RK,  1992 FXRP

kd

Quote from: 1340evo on November 22, 2021, 07:58:24 AMso the colder it get's, the leaner it gets?...  are you sure?

Cold shrinks most things and that makes them denser by volume. The air flow is a constant determined by the throat size of the carb and throttle valve position.  The same volume of denser air equals more oxygen in the mix.  If the fuel remains metered at the same jet size that will mean the air fuel ratio tips over to more air but the same fuel.  The air / fuel ration is therefore leaner in cold weather.  A good example is having to use the choke longer in cold weather startups or the engine spits back through the carb (typical lean response).
KD

JW113

Every time I've popped one of those N65C ('88 sportster) needles in on of my bikes, I've taken it back out. EVERY time.

Just sayin'...

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

Yes, from how it was, I'd say lean for sure. What KD says is just what I experianced.
I never got it on the AFR meter this summer as the return spring went in the greabox so had to set about doing that with my limited time, but this does give me some idea its probably not far off. I've still to put 50 miles on it to finish running it in LOL

So what do people do who use their bikes summer and winter in the US as I'm sure the temp extreames are worst there than they are in the UK ?

Hossamania

As far as my CV carbs riding in extreme cold and extreme heat, they have always done well once dialed in. No jetting changes made due to weather, I just ride it and it works well. Choke on a little longer in the cold, and an occasional cough in extreme cold (30°F) roll on when the motor isn't quite hot, but no real issues. Worked from near sea level to 11,000 feet. I do not lug the motor.
If the government gives you everything you want,
it can take away everything you have.

kd

November 23, 2021, 02:29:49 PM #67 Last Edit: November 23, 2021, 02:34:34 PM by kd
Quote from: Hossamania on November 23, 2021, 01:41:33 PMAs far as my CV carbs riding in extreme cold and extreme heat, they have always done well once dialed in. No jetting changes made due to weather, I just ride it and it works well. Choke on a little longer in the cold, and an occasional cough in extreme cold (30°F) roll on when the motor isn't quite hot, but no real issues. Worked from near sea level to 11,000 feet.  I do not lug the motor.

This is important.  Most of the adverse reactions happen at low RPM when the intake isn't really flowing yet.
KD

Hossamania

Quote from: kd on November 23, 2021, 02:29:49 PM
Quote from: Hossamania on November 23, 2021, 01:41:33 PMAs far as my CV carbs riding in extreme cold and extreme heat, they have always done well once dialed in. No jetting changes made due to weather, I just ride it and it works well. Choke on a little longer in the cold, and an occasional cough in extreme cold (30°F) roll on when the motor isn't quite hot, but no real issues. Worked from near sea level to 11,000 feet.  I do not lug the motor.

This is important.  Most of the adverse reactions happen at low RPM when the intake isn't really flowing yet.

I should also have mentioned, the carb coughs so rarely that it completely surprises me when it happens.
If the government gives you everything you want,
it can take away everything you have.

kd

Air velocity is your friend.  :wink:
KD

JW113

What he said. (Hoss, that is) Pretty much sums up my experience with them to the T. Regarding temp extremes in the UK compared to the "USA" (very, very big place spanning many climactic zones), I think you need to be a little more specific. I went out for a lunch ride today in a T-shirt and vest. So, probably a wee bit warmer here than in the UK right now.
 :SM:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

It was 3 deg C (37F) last week, but that said summer is typicaly 20 deg c or so (70F), so not that much differance.
It does run poor on the choke like just on the front cylinder, but it always has.take out the plugs the front will be darker, but the rear will be a bit black... I need to investigate this a bit more. But with the choke off, it runs good and the plugs are exactly the same...

Hossamania

November 25, 2021, 07:59:50 AM #72 Last Edit: November 25, 2021, 08:15:13 AM by Hossamania
Delete, new post to come.
If the government gives you everything you want,
it can take away everything you have.

bobrk1

I had  a  97 rk headquarters  heads, slip ons  hq  cam , ran a   50 slow  and  200 main. Did  slow  jet just  crusing  around  and  check  plugs. Main go on highway  around  65mph  and  go wide  open  for  a few  seconds  then  back  off 1/8 on the  throttle  if you  feel  it pull it's  lean. I had  it put  on dyno  after  and  he  said  it was  good  right  there ,  gave  me  2 shims  to  raise  the  needle . Needle  was  from  1200 sporty , dealer said  that  they  never  go bigger  than  180, lol glad  I  did  my own .

bobrk1

I  had  a  97rk  with  se  air  cleaner , headquarters  heads  and  cam  and  slip on  mufflers . I  tuned  it so it was  running  great  then  went  to  dyno  for  a  better  tune . Dealer  said  they never  went  bigger  than  180 on main . I  had a 50 low ,200 main  with  a  1200 needle , when  he  ran  on dyno  he  said  it  was  right  on, except  he  gave  me  2 shims  to  raise  the  needle  and  played  with  timing  a little .

1340evo

Wish someone in the UK had CV bits to do this on a dyno.
May have to invest in a sensor kit for the front pipe and do it myself...

JW113

Why not? I don't know what dyno tunes are in the UK, but here in the USA, you can buy an AFR and roll your own for less than a dyno tune. I have a Daytona Sensors, but I saw this one and thought it was pretty cool, not to mention, very affordable:

https://www.safrtool.com/shopping/viewSAFR.asp?pid=1

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

That could do with some pictures but guess I see how it works. Or just drill and weld on a senso bush... will have a look ans see whats about ;)

JW113

That's what I do, weld a bung in the pipe. All depends how much you fancy style and aesthetics.
 :SM:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

I have V&H pipes so thet come with a cover to the front, not sure you'd see a bung on the back that much, and obviously plugged when not in use. We have expert welders at work also so would look like it's meant to be there :)

1340evo

Update on this post having found a bit of time and fitted a AFR.

so started testing last week and was shocked to find it very lean almost everywhere! When you rode the bike and brought it home, youd hear a tink, tink, tink, sound from the exhaust as it cooled down. Having messed with it for a week its not making that sound now so guess it running a tad cooler. So this is what I found :-

7.7.22 45 / 180 2.5 turns N65c No shim   Runs way lean most places, seeing some 16.5's under load!
8.7.22 45 / 180 2.5 turns N65c .030shim  Runs better, still lean at top and acceleration, constant 13.5, top 14.5
9.7.22 45 / 190 2.5 turns N65c .030shim  12.7 tickover, 1/8 turn 15's, WOT 14 through range
15.7.22 46 / 190 2.5 turns N65c .030shim... still to test

So will work on the bottom end and getting that right as it impacts to top end also. Acceleration is where it leans out a lot?.. looks like I'm heading back to 48 / 190 at least ....

JW113

I don't know if there is a right way or wrong way, but here is what I do.

Take a AFR baseline of idle, steady cruise in 3rd gear at 40mph, steady cruise in 5th gear at 70mph, and WFO in 4th gear from 40mph to 80mph.

Idle is set with the idle screw of course, and shoot for around 12.8.

The two steady cruise readings are about economy/mileage, and you want somewhere above 13.8 or even in to the low/mid 14s. I shoot for 14.4. This is mostly managed with the pilot jet, especially the 3rd/40mph reading, the 5th/70mph reading is by the needle & shims but also the pilot jet. It gets to be a bit of an aggravating balancing act.

Full throttle is where you really need to be concerned, as at idle and cruise, running lean is not so much a big deal as the amount of heat (from the fuel) being created is far less than at WOT. Here you need to be at the very least below 13.0, and closer to 12.5. Running lean at WOT creates a lot of heat, can be dangerous for the engine. Main jet, along with shimming the needle, will dial that in.

I, like you, was shocked the first time I hooked up an AFR gauge and saw how lean the thing was, especially on my Shovelhead. Due to the lousy combustion chamber design, they require a hell of a lot more fuel than an Evo or TC. After spending some time on both Shovelhead and Ironhead to get the AFR tuned correctly, it is simply amazing how much better they run. Need to get around to doing the same to my Evo, I have no doubt what-so-ever that it is lean as hell. My TC 'King was tuned on a dyno so I suppose it's close, but might as well do that one also someday.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

kd

I will add that having 3 circuits controlling low mid and high rpm influenced by manifold pressure (vacuum) I have found it best to keep the influence of each circuit close to the next.  By that I mean too large of a step to the next circuit will cause running issues like stumbling or bogging.
KD

1340evo

July 16, 2022, 12:25:26 PM #83 Last Edit: July 16, 2022, 12:52:22 PM by 1340evo
Quote from: JW113 on July 16, 2022, 09:11:33 AMI don't know if there is a right way or wrong way, but here is what I do.

Take a AFR baseline of idle, steady cruise in 3rd gear at 40mph, steady cruise in 5th gear at 70mph, and WFO in 4th gear from 40mph to 80mph.

Idle is set with the idle screw of course, and shoot for around 12.8.

The two steady cruise readings are about economy/mileage, and you want somewhere above 13.8 or even in to the low/mid 14s. I shoot for 14.4. This is mostly managed with the pilot jet, especially the 3rd/40mph reading, the 5th/70mph reading is by the needle & shims but also the pilot jet. It gets to be a bit of an aggravating balancing act.

Full throttle is where you really need to be concerned, as at idle and cruise, running lean is not so much a big deal as the amount of heat (from the fuel) being created is far less than at WOT. Here you need to be at the very least below 13.0, and closer to 12.5. Running lean at WOT creates a lot of heat, can be dangerous for the engine. Main jet, along with shimming the needle, will dial that in.

I, like you, was shocked the first time I hooked up an AFR gauge and saw how lean the thing was, especially on my Shovelhead. Due to the lousy combustion chamber design, they require a hell of a lot more fuel than an Evo or TC. After spending some time on both Shovelhead and Ironhead to get the AFR tuned correctly, it is simply amazing how much better they run. Need to get around to doing the same to my Evo, I have no doubt what-so-ever that it is lean as hell. My TC 'King was tuned on a dyno so I suppose it's close, but might as well do that one also someday.

-JW

Thanks, thats great info indeed, I'll print it off and take it with me to make notes. Problem is trying to remember everything after a run, If you just target a couple at a time and go from there I guess.

When I initialy set the bike up seat of pants I was at 190 / 48 and a .030 shim, but allowed myself to be talked down to the smaller jets. But having put the AFR on there, I didn't think it was working right, but its amazing how 185 to 190 changes the AFR a lot.

Also, a lot of people are quoting 12.5's to 12.9's, Its good to see you saying 14's in places as I know now I'd be going too big.

On WOT from to to bottom of the rev range its bouncing around the 14 mark which by changing the low jet may now be addressed, but I'll follow what you say and see how I go.

Where it does go lean now is by just opening the throttle a tad at any speed so need to sort that one, but will do as you say above  :up:

One question I have. when setting or chosing the pilot jet, do you take any pre-set gap from the butterfly? I've tried to follow instruction on setting this before but its never worked, but there again, the idle is set on the butterfly screw right? so to get the bike to stall etc on the air screw, do you have to back this gap off???

1340evo

Quote from: kd on July 16, 2022, 09:42:37 AMI will add that having 3 circuits controlling low mid and high rpm influenced by manifold pressure (vacuum) I have found it best to keep the influence of each circuit close to the next.  By that I mean too large of a step to the next circuit will cause running issues like stumbling or bogging.

Yes, was reading today some guy who's set the bike up and had a 42 slow running and a 195 main and thinking that can't just be right. As you say, things have go to work together  :up:

JW113

Try to keep in mind where the fuel is getting into the engine at different throttle settings.

Idle: From the idle port. Primarily controlled by the idle mixture screw, at far back of carb on the bottom side.

Steady cruise: From the transfer ports just under the throttle place at very low throttle positions 90 to 1/8), along with the main port at higher throttle positions (1/8 to 1/4). Controlled primarily by the pilot jet at low throttle, and the needle at higher.

Full Power WOT: From the main port, primarily controlled by the main jet but needle also.

From 1/4 throttle to WOT, it's a balancing act of needle type and shims.

Full power WOT you want to be down around 12.5 for max power.

At cruise, you want to be leaner so's to get reasonable fuel mileage, I shoot for 14.4. As you have found, you can have the motor quite lean, into the 15s or more, and it will still run. But anywhere around stoichiometric (14.7) and higher, the combustion temp gets quite high. At low throttle positions, the motor can likely take it. At WFO, that lean is in the danger zone.

Try not to make more than one carb adjustment at a time, and try not to focus on all the areas of tuning. Get one dialed in, move on to the next. There will be a lot of rechecking and re-tuning along the way, can be kind of frustrating. Think of it as a game.
 :SM:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

July 17, 2022, 01:22:05 PM #86 Last Edit: July 17, 2022, 01:29:00 PM by 1340evo
Okay, so I did a few test runs as I'm set now but I'd changed from 45 to 46. think thats a bit OTT as at 1 1/4 turns I'm only getting 11.5 where as on the 9th July with my 45 jet at 2 1/2 turns I was getting 12.7 which was about perfect I think....

9.7.22 45 / 190 2.5 turns N65c .030shim  12.7 tickover, 1/8 turn 15's, WOT 14 through range
17.7.22 46 / 190 1 1/4 turns N65c .030shim... 11.5 tickover, 3rd at 40 11.8, 5th at 70 13.8,
4th WOT from 40 to 80  40 12.5 / 60 11.5 / 80 14.5

so from that what would you suggest? maybe the whole thing is no good as my idle was rich so does that screw everything? got to say, reading the numbers on the AFR is not easy as they do jump about a bit.. On most of the above I've done a few runs and these are the figures I think are representative

turboprop

Seems you have confirmed the size of the intermediate jet that is needed. Have you considered looking at needles with different profiles?
'We' like this' - Said by the one man operation.

speedzter

Don't forget you really need to check both front and rear cylinders, and average out the Afr between the two.

JW113

Damn dude, he'll never get done with this doing that!
 :hyst:

If this were racing, i.e. drag racing, and for money, sure. For a ride around town bike, waste of time. At least in my opinion. Get one jug tuned within reason, and have fun with it. The other jug's breathing through the same carb so it can't be *that* far off.

As Turbo said, maybe a different needle. I don't really like those N65C needles myself. They have a smaller diameter at the top of the taper to compensate for no accelerator pump, but they were still used in a sportster, so the diameter at the tip is bigger than a big twin.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

Yup, I'm going to take it the rear jug is okay from doing the front. Looking at the plugs they both look the same so no reason to think it's not getting the same supply from the carb.

I can try needles for sure, but would be guessing as I know little about them and their relation to each other

So for now, I'll go back to 45, and I have a 195 on order to try.

One thing I've reported before, as you just start to open the throttle it does go quite lean from any given RPM at cruse. I guess the carb has to catch up with demand but it appears to take a long time, so is the slide working as it should. I wil check the hole in there to see what size it is ;)

JW113

Don't worry about it as you crack the throttle. Yes, will always go lean briefly until the main circuit starts to see "signal", i.e. vacuum, to pull the fuel up. Hence, accelerator pump. Focus more on steady state.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

turboprop

'We' like this' - Said by the one man operation.

1340evo

July 21, 2022, 12:48:28 PM #93 Last Edit: July 21, 2022, 12:55:55 PM by 1340evo
Right, tried the 45 / 195 but never got to the top end due to rain :(
but 70 in 5th is about 14.2
and 40 in 3rd is about 13.5
Tickover back at 12.8 on 2 1/2 turns So that lots good

What I'm still seeing is from just cruising on not a lot of throttle, to just opening a bit more but before it hits the injection pump, it goes very lean for as long as it sits there... say its a flat road and you are doing 50 but want to go a tad faster so you just crack it open a bit and lean it goes until you trottle back, or go further...
its like the pump needs to come in sooner, but even if it did, it would not last after the initial squirt, or the slide need to go up quicker.... Or I accept its a lean area?
Open it a bit more where it hits the pumpa and its fine down at 13's...
Is there anything I can do to improve this area at all? as was thinking of .030 more under the needle but think its a lower rpm where I'm seeing it....

Hossamania

Which gear are you in at 50mph?
If the government gives you everything you want,
it can take away everything you have.

1340evo

July 21, 2022, 02:16:46 PM #95 Last Edit: July 21, 2022, 02:56:22 PM by 1340evo
4 th i guess, okay may be going a bit slow for the gear, but it will do the same at 50 in 3rd for example if you just twist it that little bit more....
I'm going to shim the needle more but think the issue is before the slide moves anyway?

turboprop

Seems you now have the low and high speed jets confirmed as well as the idle mixture screw. All that is left is selecting the correct needle, adjusting its height and maybe playing around with different slide springs and slide ports.

FWI - Most members of this forum will be very quick too chime in with 'Dont drill the slide' but very few of them have ever drilled a slide or tuned a carb with an AFR like you are doing. It is just the nature of online forums. I suggest you get a couple slides and springs and maybe a flat bowl with an adjustable fuel pump.

Adjustable Harley CV Float Bowl.
'We' like this' - Said by the one man operation.

Hossamania

I will admit I have not drilled a slide, and so I should not have recommended or discouraged it without first hand knowledge.
I don't consider 50 mph in 4th gear to be too slow for the gear, that is about the right cruising combo for that speed and gear.
If the government gives you everything you want,
it can take away everything you have.

1340evo

That adjustable pump looks interesting for sure.. yes, I'll get a new slide and I can play about with the old one... also needles but which way to go there?

turboprop

Quote from: 1340evo on July 21, 2022, 11:27:11 PMThat adjustable pump looks interesting for sure.. yes, I'll get a new slide and I can play about with the old one... also needles but which way to go there?


All four of them.
'We' like this' - Said by the one man operation.

turboprop

Quote from: 1340evo on July 21, 2022, 11:27:11 PMThat adjustable pump looks interesting for sure.. yes, I'll get a new slide and I can play about with the old one... also needles but which way to go there?

Unlike a Mikuni HSR series pump. Your CV carb with this aftermarket float bowl will still lack the tuneability of the HSR in that while this bowl has adjustable volume it still lacks the ability to adjust the start and stopping points for when the accelerator pump operates. Increasing the volume of the accelerator pump like this will have a global affect on gas mileage.

Surprised that nobody has chimed in about disabling the accelerator pump during tuning. The manual for the HSR calls this out. As does the instructions for the S&S Super carbs. The CV is no different. You should really disable the accelerator pump in that CV and make a few steady state pulls at different throttle openings and then activate the accelerator pump and dial it in. I suspect that if you were to obtain all four  of the needles and re tune without the accelerator pump in play that you would probably end up in a better place at the end.
'We' like this' - Said by the one man operation.

1340evo

Tuning (messing about in a controlled manner) to continue this weekend if its dry  :teeth:

JW113

OK Turbo, good point about the effect of the accel pump, but that is why I basically ignore what the AFR has to say right after a throttle change, and focus on what is going on a few seconds afterwards after that shot of fuel has been purged through the motor. I tend to tune more for steady state, as that is how I typically ride. And I'm categorizing WFO as steady state (for passing). Hold it WFO and read the gauge after the accel pump shot has cleared through. That is not to say that disabling it completely is not a better method, and yes thanks for pointing that out.

I also have not messed around with drilling slides or playing with springs. Call me lazy. Or maybe even  that I'm easy to please. The older you get, your focus on what is important tends to shift.
 :SM:

But at the end of the day, these AFR gauges totally rock.
 :beer:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

I agree, they do indeed, to the point where you can see everything. So maybe trying to fix every last issue is not realistic.
I've ordered a slide with a new rubber (looks like they all come from China now) because I have a bit of melt on mine so can have a play when its here, and did think pushing the slide up yesterday that the spring was quite heavy so to address my 'quicker responce' issue, that may be worth a try. But as you say, its now 90% better than it was and safe so even if I called it a day today, it would be sorted much better than it was.

I always advise people not to fit a gauge (oil pressure, temp etc) if you don't need to as 10:1 you'll identify a problem and spend hours and $ trying to fix it, however long its lasted this far  :wink:

See what my ".060 os shims does this weekend if its dry :)

turboprop

Quote from: JW113 on July 22, 2022, 10:16:11 PMOK Turbo, good point about the effect of the accel pump, but that is why I basically ignore what the AFR has to say right after a throttle change, and focus on what is going on a few seconds afterwards after that shot of fuel has been purged through the motor. I tend to tune more for steady state, as that is how I typically ride. And I'm categorizing WFO as steady state (for passing). Hold it WFO and read the gauge after the accel pump shot has cleared through. That is not to say that disabling it completely is not a better method, and yes thanks for pointing that out.

I also have not messed around with drilling slides or playing with springs. Call me lazy. Or maybe even  that I'm easy to please. The older you get, your focus on what is important tends to shift.
 :SM:

But at the end of the day, these AFR gauges totally rock.
 :beer:

-JW


JW, I am not a smart person, but I know a few and can identify the smart people in a room. I tend to do what they say or do. Works for me.

The smart people at S&S and Mak say to disable their accelerator pumps during tuning and do them last as they will mask conditions that can be tuned out with jets. Same thing applies to a CV carb regardless of an adjustable accelerator pump being used or not.

I am also pretty dig on people simply repeating what they have read online without any experience doing or seeing whatever they are posting about. IME, not drilling the slide and the spring is one of those things that gets posted by many as a knee jerk reaction whenever a topic like this comes up. I suspect that very few  of the posters in the 'Don't drill the slide' gaggle have never done so themselves. This is like a self licking ice cream cone. This thread is a perfect example of how drilling a slide or altering/changing the spring might be an improvement.

I rarely get involved with this level of detail in threads like this but I like how the OP is going abut this. He is actually doing stuff. So here I am.

So, with the accelerator pump rod disabled the jetting becomes isolated and the tuner will have finer resolution on how the engine is responding to changes to the carb. I hope the OP follows through with ordering the needles, continues his A-B comparisons of them and moves the ball a bit towards tuning nirvana.  Drilling the slide (or sealing the hole and drilling a smaller hole) and trying springs with different spring pressures will be educational and should gain the OP a few more yards. The aftermarket float bowl with an adjustable accelerator pump with increased volume will be the final piece to cross the goal line.

To the OP, I rarely do this, but I have given you a pretty good plan of action. I hope you follow through with most of this stuff as it will provide a really good example of how precise a CV carb can be tuned and dispel a few internet myths.

I will also share with you that JW was initially very reluctant to get or use an AFR gauge. He was chasing his tail tuning something. I knew the answer but instead of serving it up on a silver platter I encouraged him to get an AFR gauge and learn for himself. He got an AFR, tuned that bike very well and is now a big advocate of using an AFR gauge to tune carb'd bikes. I suspect that after this thread JW (and others) may re-look their tunes and their reluctance to altering the slide and/or spring.

Final thought. The float bowl with the adjustable pump has come up on this forum a few times. Search, it is here. You will see a bunch of negative responses from posters that have said they have not used it. This thread really highlights why Boyesen went IRAD to develop it. They are smart people and they saw a need/requirement for it. This is it. I am anxiously following this thread.

-TP
'We' like this' - Said by the one man operation.

JW113

Naaaah..

 :SM:

LOL. Not to say that you are not correct, because obviously you are. However, there is tuning to make the AFR gauge happy, and there is tuning to make ME happy. If I achieve the second one, then I don't spend much more time on the first one. Hey, I said I'm lazy, right?

On that note, my impression is that the slider hole and spring have more transitional fuel metering than it does with steady state metering. And perhaps rate of change of air flow as well I suppose. I do know that one of the 'complaints' about CV cab is their lack of "responsiveness" meaning they don't snap to action the way a butterfly carb (ala S&S) does, which gives the perception of more power. The hole/spring function to dampen the rate at which air flows changes through the carb after throttle plate changes, especially rapid changes. Like a shock absorber. I actually embrace that. The thing I hate most about S&S carbs is how twitch they are. I suppose on the race track, nobody cares and is probably an advantage, but on the totally worn out crap roads here in San Jose, every little bump you ride over gets transmitted to the right side handlebar grip, and you end up with a bike that wants to jerk and surge. No thanks, but thank you CV for damping out that crap.

Yes, yes, yes. You absolutely sold me on the value of an AFR gauge, and to that I owe you a big THANK YOU. I drank the cool aid, and now am a firm believer, and preach the AFR gospel every chance I get.
Was one of those life changing deals, actually.

Great info Turbo, and always appreciated when we can lure you out of your lair and share some of your knowledge.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

July 23, 2022, 09:33:34 AM #106 Last Edit: July 23, 2022, 09:41:23 AM by 1340evo
Thanks for all your input guys, its an education doing this as I thought I was quite close before. But the AFR gauge has been a revalation for sure. As you say, how many others out there think they are close and maybe this is why so many bikes do "Potty mouth" pistons and valves because they are just set up wrong.

I for one would never think a 45 and a 195 jet would run together to give the best results... I used to think go up on one so the other must follow and the other way for coming down.

Okay, I do have V&H exhausts which we know are not the best, but out of the threads I have looked at, those who were saying 45 / 195 or even 200 with drag pipes where not that far out, but I'd dismissed them before as not knowing what they were doing...

I've disconnected the pump earlier today as you said and will see what that tells me.
Also reading many posts and trying to stear a way through the dross out there, it does sound like drilling the slide is worth a try.
The 1/8 hole is too big and will bog down on acceleration, but the hole I have now is spot on 2.5mm so what people have done for lighter bikes (which mine is) they have drilled 7/64" or 2.75mm which sounds to work well and may solve the problem I have.

Also using a spring from a CV44 27728=99 appear to be a thing as its shorter and has a reduced rate. If thats not available by cutting 3 coils from the existing spring, you get the same end result.

At least I have options to play with now and see how things alter. I think before my time a cheap re-furb kit had been put on the carb so I also need to check everything out but I know the spring rate it should be now, so I can measure it...

''You can either install a DynoJet spring which is shorter and a lighter spring rate, (8.8 onces for 3" compression and 5" long VS stock which is 12.5 onces for 3" compression and 5.5" long) a stock spring, or take a stock spring, cut off 3 rings from it, and your slide will react faster, giving similar results as the DynoJet spring.''

All good fun, but at this rate it's going to take all summer to get it set up 100%.. but whats the rush.
And then you start thinking 'injection' and doing the maps for that ??.. maybe / maybe not. Got to say I do like the carbs for their simplicity once set...

I will play with needles but in the UK they are not that easy to find so will have to order from the US and await their arrival. I know measuring between the two I have here on the shadowgraph at work they differ greatly so will make a hell of a differance when in the carb.

Onwards and upwards. It's raining again so don't want to get the gauge wet.. see how it looks tomorrow  :chop:

Finn

Quote from: 1340evo on July 23, 2022, 09:33:34 AM...I will play with needles but in the UK they are not that easy to find...
You should be able to get HD needles with part number from every Harley dealer in UK. It may be that they have no stock but nevertheless.

Aftermarket companies such as Motorcycle Storehouse (and others) also have needles etc. available. They have many dealers in UK.

Motorcycle Storehouse CV Performance parts
-83 GS1000G | -84 GSX1100EF | -97 FLHR | -98 FLSTS | -16 Triumph Tiger Explorer XRT 1200

JW113

I'm not sure I'd go with stock HD needles. They were developed for street (aka EPA) engines and are tuned accordingly, i.e. "lean". You can attempt to compensate by using shims under the needle head, and I have indeed done that myself. You can also 'maybe' find one of those SE race tuner kit, but it's been so long since HD sold a bike with a carburetor on it, not sure if you can still find them. Next time I think I'd try those aftermarket needles as Turbo suggested. If for no other reason that to see how they do. But here is some stock info for you if interested.

You cannot see attachments on this board.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

turboprop

Quote from: 1340evo on July 23, 2022, 09:33:34 AMI will play with needles but in the UK they are not that easy to find so will have to order from the US and await their arrival.

Why order from the US a needle that is made in Japan? Seriously. No need to pay the Harley overhead. Buy the oem manufacture pins. Certainly someone in your country has a source for the needles that I linked to that does not include Harley.
'We' like this' - Said by the one man operation.

1340evo

Quote from: turboprop on July 25, 2022, 05:13:23 PM
Quote from: 1340evo on July 23, 2022, 09:33:34 AMI will play with needles but in the UK they are not that easy to find so will have to order from the US and await their arrival.

Why order from the US a needle that is made in Japan? Seriously. No need to pay the Harley overhead. Buy the oem manufacture pins. Certainly someone in your country has a source for the needles that I linked to that does not include Harley.

yes, you are right... I even have a mate in Japan ;)

1340evo

July 27, 2022, 01:21:51 PM #111 Last Edit: July 27, 2022, 01:59:14 PM by 1340evo
This is getting a bit strange now :- normal running it bobs about 12.5 to 13.5.. open it up a bit it will just go over 14, open it up more its 12.4 and it goes well,
as it revs the ARF climbes...
Ive now got :-
45 idle
195 main
0.060 shims,
2.5 turns
N65C

Tickover 12.7, 5th at 70 13.3, 3rd at 40 12.8, 4th 40 to 80.. too low rpm at 40, think this may be my cam as it likes to rev a bit ...anyway, bogged down a bit then climed up to 14 at 80.
If I run it real top end to the rev limiter im seeing 15.5 up there but loves it??

I now have a linear line kind of from 12.5 at the lower rev rang all the way up to 15.5 at the top end??

Switch it off and back on but without starting, the AFR reads 17 and slowley over a period of time counts up to ---- so does this suggest unburnt fuel in the exhaust I guess.

But plugs look good for the hours running about I've done



 

turboprop

Obviously the N65C needle is not working in this application. I bet if you spent less than 10 minutes looking at the chart that JW posted a solution will present itself. You have good data. Pin selection will not be a one and done process if you truly want to achieve tuning nirvana. Your next needle change will get it closer. Keep chasing it.
'We' like this' - Said by the one man operation.

JW113

If I am understanding your measurements correctly, you are too rich at cruise/part throttle, and too lean at top end WFO. I would interpret that as the needle is too high, and the main jet is too small. Try a larger main jet and see what it does to the WFO and RPMs above 3500. 15:1+ is too lean, and though it might seem to run great, it will run a hell of a lot better if you get it below 13:1.

As I said before, I did not have great luck with the N65C. It is a SPORTSTER needle. Smaller motor. It's claim to fame is it is rich in the low end, as you are finding. '88 XL was a one year only CV that had no accelerator pump (why???), and that needle was their "solution". That's all. It is not in any way a performance needle.

Last thing, you mentioned "unburnt fuel in the exhaust". That AFR meter has no idea how much fuel is in the exhaust. It measures how much unused oxygen is in the exhaust. If there is unused oxygen, then there is not enough fuel being supplied to consume it during combustion. Try not to get confused by what that gauge is telling you, focus on what it is actually measuring.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

July 27, 2022, 11:51:35 PM #114 Last Edit: July 28, 2022, 01:15:23 AM by 1340evo
Away for a week now so will get a few bits in ready for when I return.

The gauge was strange, I've never seen it do that before as its always heated up and come on at ----

But it was sat there at 17 and over I guess 5 mins, slowly counted from 17 to 21 where it went ----
so from what you say, its measuring unused oxygen which with the engine stopped I'd of thought would go to ---- more or less straight away as I only have minimal baffles??

I'll go back to my old pin first and see what that does (standard), then as you say, with a couple of sets of data, i'll be able to apply this to the pin chart ;)

JW113

Can you clarify, are you monitoring the AFR with the bike running, then shut it off, turn the key back on but not start the engine and watching the AFR gauge? If yes, not sure why you're doing that. The reading is meaningless. What's in the exhaust pipe is spent exhaust gases (H20, C02) until the atmosphere starts working it's way back up into the pipe.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

yes. went for a ride to look at what changes I'd made, came back and switched the bike off.
Then went to put it away, switched it on but didn't start it straight away. After the heat cycle the sensor goes through I was suprised to see it reading 17 on the gauge.
I'm sure when I've done this before its gone to ---- more or less straight away?
I'm not trying to measure anything obviously, just wondering if its working right?
It must of taken 5 mins before it went to ---- even blowing a bit of air up the exhaust??

Strange

1340evo

August 09, 2022, 01:37:31 PM #117 Last Edit: August 09, 2022, 01:43:20 PM by 1340evo
I'm kind of not getting this.. its like the carb or the gauge works backwards?
cruse at 50 and close throttle slightly it goes rich, cruse at 50 acceletate a bit and it goes lean. I guess this is how a CV carb works.
Down hill its ritch, up hill it leans out
Are you guy's tuning CV's or something with a more dirrect link?
I've got it now where it cruses at 14's mid range, down at lower RPM's its crusing at 13.2 area... but anything over 90 MPH its still going lean  .. how can that be I've got a 200 in there now and it should dround it! but does come down a bit if you hold it up there lets say 5.5K area.
It will do for now I guess, picks up real nice and is quite fast on acceleration. I'll see what MPG I'm getting also.
Next thing to try may be more restriction in the pipes??
Done maybe 20 miles tonight, not sure what you make of the plugs...

Hossamania

August 09, 2022, 01:45:17 PM #118 Last Edit: August 09, 2022, 01:54:06 PM by Hossamania
Are you still running V&H Shotguns? Do they have any baffles?
I just looked up Shotgun pipes, nothing with that name came up immediately. Are the called something else? Short shots? Long shots? Staggered? What diameter?
Might help to post a picture of them.
If the government gives you everything you want,
it can take away everything you have.

kd

I'm kind of not getting this.. its like the carb or the gauge works backwards?
cruse at 50 and close throttle slightly it goes rich, cruse at 50 acceletate a bit and it goes lean. I guess this is how a CV carb works.
Down hill its ritch, up hill it leans out


Remember when you close the throttle blade when rolling it off, the drive train is maintaining the rpm.  That is simple physics at work.  Closing the throttle increases manifold vacuum and with a stronger negative manifold pressure you will draw raw fuel from the lower speed circuits behind the throttle plate. (idle and mid)  That changes the AFR because you have reduced the air flow and increased the fuel introduced.  That also turns out to be a good thing as a richer mixture will reduce exhaust popping on decel.

IMO, the plugs look OK and are nice and even (as in balanced).
KD

Ohio HD

Quote from: kd on August 09, 2022, 02:01:51 PMRemember when you close the throttle blade when rolling it off, the drive train is maintaining the rpm.  That is simple physics at work.  Closing the throttle increases manifold vacuum and with a stronger negative manifold pressure you will draw raw fuel from the lower speed circuits behind the throttle plate. (idle and mid)  That changes the AFR because you have reduced the air flow and increased the fuel introduced.  That also turns out to be a good thing as a richer mixture will reduce exhaust popping on decel.

IMO, the plugs look OK and are nice and even (as in balanced).

Agree, you have to jet for idle, cruise and wide open throttle. Not for deceleration.


JW113

And one more agree. The plugs look fine, but I'm guessing that you've been on the throttle a bit. I'm getting the impression that you're paying way too much attention to that gauge during transient states. Don't! It doesn't matter. As Ohio said:

Idle: so it don't load up and foul the plugs but also starts/runs at cooler temps OK.
Cruise: for good mileage. 14.4 or higher. Even 15 is OK as long as it's steady state. Try locking the throttle and let it stabilize, then read the gauge.
WFO: For power. 12.5-ish is ideal, or something close to that.

It sounds like you're happy with the power, and that's good. Time to do a mileage test. Try a 100 mile highway ride and see how much MPG you are getting. 45 is good, mine gets close to 50.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

August 14, 2022, 04:47:51 AM #122 Last Edit: August 14, 2022, 04:52:14 AM by 1340evo
Hi All, been banned for a few days as I put a picture up on the V&H Straight Shots I have fitted... (OOps, keep forgeting that rule as its not a thing in the UK... Will try my best to remember!!).. so not Shotguns at all, no idea where that came from ...

So been to a rally this weekend with my Slave friends, a good 100 mile round trip and the bike is running the best it ever has. Just looked at the plugs and they have not changed much from the picture about so for now I'm saying it's good to ride.
I may get a CVP Velocity Needle at some point as I'm told its shorter so does not restrict as much top end (anyone got the dim's for this?) and / or try a bit more restriction in the pipes (the have the std V&H baffles right now, so quite open....
So with this okay for now, I'm going to move on to my timing again as its set stock now, maybe try a bit more advance and see how that goes.

My settings now are :-
45 pilot
2.5 turns air screw
200 main
N65c needle
0.030" shim

I also made a small brass washer to put under that main jet as the one I have appear to have 2 head sizes, so this made a shorter head into a longer head version.. not sure if it helped anything but makes it less likeley to come out of the fuel.
Suns out in the UK so its riding time so here we go.. Again, great help guy's and thanks for all the support.

To admin.. sorry for posting pics that are not mine, as I say, its not an issue in the UK but you are always quick off the block to spot and remove them  :up:

capn

That afr gauge WILL drive you crazy.

1340evo

It already has, and on a CV its probably a lot worst as the carb does what it wants depending on the vac in the manifold, where as a Mikuni I guess just delivers what you ask it to.
But having got used to it's bouncing about, it does give you a good idea for sure where you are and where you need to be...
I've gone from 180 main to 200 main and lifted the N65c by .030"... think it could still do with a bit more but thats all its getting for now.
If I'd not of fit it I'd be well in damger on the top end / freeway...

JW113

Well of course I don't see it quite that way. (surprise!) Yes, the MiK is "more" tunable. It all boils down to what do you want from the motorcycle. I personally love the CV carb, and yes they are not as tunable but they are tunable enough to provide both power and economy. I think you are still worrying about the instantaneous AFR, when in the grand scheme, it doesn't really matter. Also, you will always be fighting the time delay of that airflow driven slider witch is doing the fuel metering. I also think you are wrong about being in the danger zone, you should have done a baseline on the factory stock jetting and AFR, I think it would have scared the crap out of you. And yet, bikes with that jetting have gone for hundreds of thousands of miles with no issues. Other than lack of power, that is. Lean jetting simply means the bike is consuming all the fuel and pumping out excess air. That is fine for fuel mileage, but it is not fine at WOT for power. That is the whole point of tuning with and AFR. The EPA does not want the OEMs to tune for best power, that creates excessive carbon emissions. Some of us horrible bastards flip the finger at that and break the rules. Just like speeding, among other things.
 :SM:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Hossamania

1340, glad to hear it's running well, how is the gas mileage?
If the government gives you everything you want,
it can take away everything you have.

1340evo

I'm not saying the Cv is a problem, its a very good carb as we know and the fact millions are out there and bikes are running great is a testiment to that.
Is more what you can see with the AFR meter.. as we know, remove the air fulter and rev the bike up and down and you see the slide bounce about in responce. Its this you see on the AFR and until you get used to this, it is a bit confusing.
The thing that did strike me was the way it goes lean going up the slighlest of inclines and how much richer it is coming the other way. Unless you test on a dead flat road you see all kinds of results. what we all must do without realising is just twist the throttle a tad to compensate but once you've been riding for 40 plus years like I have, you have no idea you are doing it?
I'm sure there are bikes out there as you say, running up to 20 on the top end, but they survive and the only thing you'll see is an unwillingness to pull.

On the MPG I've no idea as its still not gone onto reserve which is good. When I was testing I could have it go on reserv the same night I filled it up but just normal running even now id say at least 45 and climbing...

kd

Quote from: 1340evo on August 18, 2022, 10:28:05 AMI'm not saying the Cv is a problem, its a very good carb as we know and the fact millions are out there and bikes are running great is a testiment to that.
Is more what you can see with the AFR meter.. as we know, remove the air fulter and rev the bike up and down and you see the slide bounce about in responce. Its this you see on the AFR and until you get used to this, it is a bit confusing.
The thing that did strike me was the way it goes lean going up the slighlest of inclines and how much richer it is coming the other way. Unless you test on a dead flat road you see all kinds of results. what we all must do without realising is just twist the throttle a tad to compensate but once you've been riding for 40 plus years like I have, you have no idea you are doing it?
I'm sure there are bikes out there as you say, running up to 20 on the top end, but they survive and the only thing you'll see is an unwillingness to pull.

On the MPG I've no idea as its still not gone onto reserve which is good. When I was testing I could have it go on reserv the same night I filled it up but just normal running even now id say at least 45 and climbing...


Because you are experimenting with the AFR gauge, here's something you may find interesting.  Before you fill the tank again, with a low fuel level around reserve(ish), warm it up and do a top end run that is long enough to eat some fuel.  Take note of the mixture reading as the run gets longer.  When you refill the tank and have a full load of fuel on board, warm it up and do a similar run again noting the AFR.  Let us know what you find.

KD

JW113

No doubt that an AFR is providing more information sometimes than you probably need to see. LOL! Again, like a broken record, get the steady state stuff tuned, and ignore the rest. It don't have to be "perfect" all the time at every throttle position and load, like EFI tries to do. That CV will take care it everything just fine if WOT and steady cruise are close. And no, 20:1 is past the point of viable combustion. But my shovel was reading 16:1 or more at WOT and was "running". No power for sure, and amazed the bee-jezus out of me after I got it into the 12's. Doh!

Knowledge is power. Too much knowledge is, uh... too much knowledge.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

Quote from: kd on August 18, 2022, 06:35:50 PM
Quote from: 1340evo on August 18, 2022, 10:28:05 AMI'm not saying the Cv is a problem, its a very good carb as we know and the fact millions are out there and bikes are running great is a testiment to that.
Is more what you can see with the AFR meter.. as we know, remove the air fulter and rev the bike up and down and you see the slide bounce about in responce. Its this you see on the AFR and until you get used to this, it is a bit confusing.
The thing that did strike me was the way it goes lean going up the slighlest of inclines and how much richer it is coming the other way. Unless you test on a dead flat road you see all kinds of results. what we all must do without realising is just twist the throttle a tad to compensate but once you've been riding for 40 plus years like I have, you have no idea you are doing it?
I'm sure there are bikes out there as you say, running up to 20 on the top end, but they survive and the only thing you'll see is an unwillingness to pull.

On the MPG I've no idea as its still not gone onto reserve which is good. When I was testing I could have it go on reserv the same night I filled it up but just normal running even now id say at least 45 and climbing...


Because you are experimenting with the AFR gauge, here's something you may find interesting.  Before you fill the tank again, with a low fuel level around reserve(ish), warm it up and do a top end run that is long enough to eat some fuel.  Take note of the mixture reading as the run gets longer.  When you refill the tank and have a full load of fuel on board, warm it up and do a similar run again noting the AFR.  Let us know what you find.



Yes, I've already seen that when the tank is full it runs a bit richer.
I put a small tube under the head of my 200 main to make it the same head hight as the 180 jet I have as I thought it may be introducing bubbles at WOT on the top end.. Im not sure if it changed anything but the brass tube is still in there.
I have it the tank near empty and did run the fuel just to see if the flow was good and it is.. I'm sure it will keep up but for sure, the float level will drop...

1340evo

Quote from: JW113 on August 19, 2022, 01:53:00 PMNo doubt that an AFR is providing more information sometimes than you probably need to see. LOL! Again, like a broken record, get the steady state stuff tuned, and ignore the rest. It don't have to be "perfect" all the time at every throttle position and load, like EFI tries to do. That CV will take care it everything just fine if WOT and steady cruise are close. And no, 20:1 is past the point of viable combustion. But my shovel was reading 16:1 or more at WOT and was "running". No power for sure, and amazed the bee-jezus out of me after I got it into the 12's. Doh!

Knowledge is power. Too much knowledge is, uh... too much knowledge.

-JW

Too much info is correct.. I'm good with it now, no pops, bangs, farts or anything so need to see what MPG I'm getting.
So will have a play with the timing next.. Which way to go with the back plate to see if I get ping, then back it off a bit ;)