95 Heritage (evo). I just put an EV27 in there. Very soon after the swap I took the CV off to do a rebuild + swap out the plastic fuel inlet for a brass one. Cracked the body while pressing it in.

bought a cheap Chinese cv carb to experiment with. I noticed the jets are different threads. Finally got it running I think well, with THEIR labeled 42 and 180. (Who knows if it’s comparable, their emulsion tube also looks different).

was quite happy, not running lean or rich as far as I could tell. This bike is new to me so I’m still figuring it out, but I noticed that on low RPM , mainly in 1-3 gear, the bike does not run smooth. It doesn’t really happen when I put on the throttle and truly accelerate. I think it’s only happening when RPM is low and constant.

is this a fuel/carb related issue or something with the tranny/clutch? What can I do to further test?

Plugs are new. New fluids all the way around.

 

Did you replace the carb to manifold seal? Have you ever replaced the manifold to heads gaskets?

Did you attempt to adjust the idle mix screw?

 

yes to Carn to manifold seal

No to throttle body gaskets

Yes to idle mix screw.

i had the same thought about the gaskets…is there a way to diagnose the throttle body gaskets other than just replacing them?

 

OK. I know a HD CV in and out but no experience with the Copy version but several on here have had OK luck.

The accepted method to check those is to spray all over when idling an listen for a change. I've found that way to be a waste of fluid.

With the age of the bike, unless they have been changed within the last 5 years, best to go ahead and replace them, eliminate any question.

 

jets are easily checked with a wire gauge or drill bits (use the solid end not the twisted)
mark the throttle and see where the range is. you are running on the idle and transfer circuits you need to play with the jet and mix screw. if you are above that need to look at the main circuit. some carbs you can install the emulsion tube upside down. if you can, run cleaner off and use a mirror to see if you have slide flutter, a common defect when people drill the lift port thinking it will help performance. truth told, the signal travels faster in a smaller diameter reason why automation used 1/4 for sense and 3/8+ for control.
knock off must be diff. i never used one on an hd but they work well with lawn equipment and in many cases cheaper that a rebuild of OEM.

 

OK. I changed the intake seals. Glad I did. I think it has a little better idle, but the problem is still there.

i noticed the bike had a snappier rev when warming up. Once the choke was all the way in, the snap left and there was some hesitation. Is this indication of it being too rich?

can’t spot a difference when adjusting the air/fuel needle. Currently at 2 turns out.

edit: after idle and a little test ride I checked plugs. Immediately spotted black, so I guess it’s too rich..but my pilots already at a low 42???

 

Found this to be off. Front looks better, rear is darker for sure…could this indicate a worse seal on the rear intake seal when I was doing it?


edit: might need to disregard these..I forgot I did a brief test with a large pilot jet and a Harley OEM emulsion tube. The knockoff did NOT like it, so I went back to its emulsion tube with just 2 holes. Will put in a new set of plugs to see where we are at.

 

Plugs look fine, switch cylinders and they'll both look the same next time.

The difference in throttle - it's way lean with the choke off. And/or the slide in the copy has a large vacuum hole and/or light slide spring.

Do you have the hose to the voes connected?

Choke is what blacks the rear plug more.

 

I attached the voes. It was a pain to get on lol

What do you think of these plugs. They do not smell like gas

 

They haven't been run enough to color much. When one is jetted correctly, they will look almost like that after 500 miles but there's a danger in that...

Doesn't matter how much too lean it is provided there is zero intake leak. Most of those copies came with lots of extra jets. Let's assume they are marked close, put a 45 and try it. About 45/185 is what you want with cam, depending on the exhaust.