Right cylinder running lean

[John Ritter]

Rarely but it can happen that a pressure test will pass but a vacuum test will fail. Pulling oil past the right crank seal will lean you out. Vacuum at 5 or 6 psi should let you know if that is the problem. I've heard of but never experienced a base gasket allowing pressure to hold and vacuum to fail. Just as a side note when installing base gaskets don't allow the inside edges to overlap.

[Rhino363]

Yeah everything looks good that I have checked so far. Starting to think about looking more into the left side to see if something is making it rich.

[m in sc]

swap carbs left to right. just cap the choke crossover. see if it follows the carb. 

[Rhino363]

Yeah brass balls are drilled out and air jets cleaned and tapped and plugged off with 5mm set screw in a couple threads.
If one ring was stuck on a piston would it cause that side to run lean or rich?
Starting to think maybe something other than carb or air leak

[m in sc]

beats me but i think you're reaching. however a top end inspection is never  bad idea if just for peace of mind.

[quocle603]

Yeah, I would see if your top end is fine. I opened up my bike and discovered a destroyed top end (and it still wanted to run). It sounds like you're going through all of the motions to figuring it out.

[Rhino363]

I swapped carbs side to side and it followed the carb. So definitely a carb issue not sure which carb now if one is lean or the other is rich. I have had them apart several times soaking in carb cleaner and new mikuni jets. Drilled the brass balls out and plugged with set screws a couple threads. Going to go back thru them again. 

[m in sc]

there you go. now you're on the right track. 

[quocle603]

Hmmm, I wonder if its the carb body or the actual brass parts inside...You may have an airleak somewhere on the carb giving you extra air to your mixture.

[m in sc]

if anything id suspect jet tube had an issue. did you get new jet tubes? rarely is the body the issue unless somebody modified something previously.

[rodneya]

are you using genuine Mikuni Jets?
Some of the aftermarket jets are all 0ver the place with sizing

[Economy Cycle John]

I swapped carbs side to side and it followed the carb. So definitely a carb issue not sure which carb now if one is lean or the other is rich. I have had them apart several times soaking in carb cleaner and new mikuni jets. Drilled the brass balls out and plugged with set screws a couple threads. Going to go back thru them again.

did you ream the airjet after you took the ball out? You should be able to see the end of the reamer/wire if you look up through the jet tube, that way you know you've cleared it.

[teazer]

And are the jest all new genuine Mikuni ?  Try blasting wd40 through the jets and compare left to right and then repeat on all the drillings/passageways.  Could be as simple as a blocked pilot bypass hole.

And did you set the fuel levels?

[Rhino363]

Everything has been cleaned and wire thru passages I can get to.all new mikuni jets. I didnt set fuel height just the float height but I have swapped floats between the carbs with no difference. Is it ever common to run larger jets in one carb? I didnt replace the main nozzle that the main jet threads into but they look to be ok.
Thanks

[m in sc]

on a streetbike? no. somethings wrong w the carbs for sure.