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Old Aug 21, 2023 | 08:00 PM
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Ive been putting some miles on my old evo lately while my newer bike is apart. Its been a long time since I messed with it.

Its a 99 softail bored .020 over, Wiseco forged pistons, balanced crank assembly, heads ported / shaved, thunder monster baffles, andrews ev27 cam, hooker long drags.
I put
27492-96A carb, w intake, all new intake gaskets. Started with 190/48 jets. 48 too lean on low rpm (stumbled). Changed to 50 jet- corrected low rpm stumbling issues. Had hesitation on transition to main jet- possibly too rich. Changed to 185/50 jets and I just quit on it a few years ago. Now Im back at trying to get it right.


It runs pretty ok. Takes off like a bullet and has good power over 80mph, but, I guess its the transition between jets. When I am running 55 or so and hit the throttle its almost like acceleration slows down, then after I get past that “dragging” range of throttle it takes off. Kinda hard to explain. Hope this makes sense. I realize the pipes are probably detrimental to the performance but I like the look & sound.
Any ideas what I should try next?
 

Last edited by LRS; Aug 21, 2023 at 09:15 PM.
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Old Aug 21, 2023 | 10:00 PM
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Need to address the needle on your CV for a start plus making sure the accelerator pump is working
 
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Old Aug 22, 2023 | 09:00 AM
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Originally Posted by 1997bagger
Need to address the needle on your CV for a start plus making sure the accelerator pump is working
Tho I very rarely use the accelerator pump...Mine are turned Off...
Is it different with Roll-On vs sudden Wack of throttle?? The CV, By Nature rolls-on...and it just may be too Much accelerator Pump!!!
 
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Old Aug 22, 2023 | 06:30 PM
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Also make sure the float level is correct, and the air bleeds are clean and the diaphragm is OK before going to jets.
 
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Old Aug 22, 2023 | 07:17 PM
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I will investigate more over the weekend. I dont know alot about these carburetors, so it will be interesting.
 
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Old Aug 22, 2023 | 09:26 PM
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Originally Posted by Racepres
Tho I very rarely use the accelerator pump...Mine are turned Off...
Is it different with Roll-On vs sudden Wack of throttle?? The CV, By Nature rolls-on...and it just may be too Much accelerator Pump!!!
Watching a CV accelerator pump hit with a Wego 3 it puts some fuel in but no changes to the needle have been made for a modified engine, it's running lean in the cruise area, a CV accel pump doesn't bog a stock engine, it won't bog this one. A 50 low jet is enough to run a 90hp engine, the 50 is carrying over into the needle crossover area trying to mask the lean area, after clean up from the 50, accel pump hit, the engine is lean from a stock needle still being present, put a Sportster or CV performance needle in it's a go if no mechanical issues are present.

 
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Old Aug 22, 2023 | 10:26 PM
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Originally Posted by 1997bagger
Watching a CV accelerator pump hit with a Wego 3 it puts some fuel in but no changes to the needle have been made for a modified engine, it's running lean in the cruise area, a CV accel pump doesn't bog a stock engine, it won't bog this one. A 50 low jet is enough to run a 90hp engine, the 50 is carrying over into the needle crossover area trying to mask the lean area, after clean up from the 50, accel pump hit, the engine is lean from a stock needle still being present, put a Sportster or CV performance needle in it's a go if no mechanical issues are present.
Is this what your talking about?




 
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Old Aug 23, 2023 | 06:05 AM
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You can shim the stock needle with one or two #4 washers which sets the needle higher and richens the mid range.
I'm pretty sure that carb had a plug over the idle mixture screw, is it removed to access and adjust it?

Just incase it's plugged,
From http://www.harley-performance.com/

The CV style Harley carburetor has a small cylindrical tower protruding from the bottom rear of the spigot (behind the bowl). The tower is plugged with a soft metal insert covering the mixture screw. Gaining access to this screw is key to fine tuning and must be remove. The metal plug is very soft and only requires a household drill and 7/64? to 1/8? bit.
Secure the carb in either a vise or by other means that will allow the carburetor to remain steady. Drill a hole into the plug making sure not to “punch” through too fast. You don’t want to damaged the mixture screw just below the plug. Allow the drill to slowly cut into the plug rather than push.
Tip: To keep from drilling too far into the plug, it has been suggested to wind electrical tape around your drill bit quite a few times about 3/16? from the tip. This will create a stop to keep the bit from drilling too deep.
Pry the plug out using a pick or awl. You can also thread a sheet metal screw into the drilled hole and use this to pull the plug out. Now that the plug is removed clean the area around the mixture screw so no metal fragments remain. At this point there are two methods for adjusting the mixture.
 

Last edited by Schex; Aug 23, 2023 at 06:06 AM.
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Old Aug 23, 2023 | 06:12 AM
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Originally Posted by Schex
You can shim the stock needle with one or two #4 washers which sets the needle higher and richens the mid range.
I'm pretty sure that carb had a plug over the idle mixture screw, is it removed to access and adjust it?

Just incase it's plugged,
From http://www.harley-performance.com/

The CV style Harley carburetor has a small cylindrical tower protruding from the bottom rear of the spigot (behind the bowl). The tower is plugged with a soft metal insert covering the mixture screw. Gaining access to this screw is key to fine tuning and must be remove. The metal plug is very soft and only requires a household drill and 7/64? to 1/8? bit.
Secure the carb in either a vise or by other means that will allow the carburetor to remain steady. Drill a hole into the plug making sure not to “punch” through too fast. You don’t want to damaged the mixture screw just below the plug. Allow the drill to slowly cut into the plug rather than push.
Tip: To keep from drilling too far into the plug, it has been suggested to wind electrical tape around your drill bit quite a few times about 3/16? from the tip. This will create a stop to keep the bit from drilling too deep.
Pry the plug out using a pick or awl. You can also thread a sheet metal screw into the drilled hole and use this to pull the plug out. Now that the plug is removed clean the area around the mixture screw so no metal fragments remain. At this point there are two methods for adjusting the mixture.
This is great info. Will check all this when I have some time. Thank you!
 
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Old Aug 23, 2023 | 09:33 PM
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Originally Posted by LRS
Is this what your talking about?



Sure is, understand they just market a needle based off a Sportster needle, a CV on a Sportster has no accell pump and the needle is richer to cover it,
 
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