Just bought this bike used for a steal, and found out it sputters when you get get to the top of each gear. It sputters, backfires, and loses power until you shift into the next gear.

It has a full muzzys exhaust on it, no aftermarket filter, but I just installed a stage 2 jet kit in it. Turned the mixture screw out 2 turns... and it still does it. The problem got a tad bit better tho. The only mod to the carb before that was it had a 146 jet, and now its down to a 142 (what the manual told me for a stage 2 at my altitude.)

So before I pay money to get it fixed, anyone have any suggestions on what the problem could be?

 

Have you cleaned the carb thouroughly? Sounds like the main jet possibly did you spray out the main jet port when you replaced it?

 

no i did not clean anything... I guess that could be my next step, but I dont see how you'd have to clean a brand new jet and the adapter that goes in first?

 

boggin and backfire at hi rpm tells me its lean, go back up in jet size and see what it does.

 

Ok so I took out the plug and it is pretty white. Has a slight yellow tint to it. So should I jeep screwing with te mixture screw or leave it at 2 turns out (what dynojet recommends) and keeping upping the jet. Or play with mixture screw with every upped jet?

 

2 to2.5 on the mixture will be fine , if plug is white I would go back to the 146 jet, these run better on the little black side

 

i put int he 146 jet and removed the airbox lid. Seems to be running fine... Has a few little spits every here and there... Im going to quit screwing with it until I get the quiet core for it. I do know for sure it was the jets tho, so the only problems I can have from there are going higher or lower on the jet.