BurnPgh wrote on 03/13/09 at 20:13:01:I've done a few things to the bike over the winter. I finally got the tubeless (yea, it actually worked out dandy. I'll fill in the details) tires on and the chain drive all finished up. I also put a raptor petcock on and heres where I may be stepping backward. After finally having gotten all this stuff finished I went for a ride. Seems after a few minutes at about half throttle the bike starts to sputter and wants to stall out. Anyone else have this issue after switching petcocks?
Assuming this happens each time you take it out...
Think ... cold engine needs choke (richened mixture), then when warm the choke is turned off (lean the mixture) in order for the engine to run smoothly and efficiently. If the choke is NOT turned off then the engine does not run smoothly, but sputters &/or hesitates.
Sounds like a too rich symptom.
The cause for the above symptom could be the float level being incorrect, or the pilot jet being too large, or the pilot air screw turned out too much, or the needle being adjusted for a TOO RICH midrange setting...or a combination of the above settings.