CV40 jet sizes

[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.

[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]

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]

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.

[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

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]

What new cam?

[Don D]

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]

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]

What new cam?

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

[Don D]

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.

[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]

[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]

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.

[Hossamania]

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.

[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

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]

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  ), 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]

He's got a big following and engine build things he does is worth watching (if you can keep awake  ), 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]

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.

[Hossamania]

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  ), 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.

[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??

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  ), 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...