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CV40 jet sizes

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

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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