Hi, my TB 250 will wheelie easily when cold, but when it warms up, it wont. It seems to loose power??

I have a HPD trailpipe, clutch kit etc, wondered if making the primary spring engage later will help?

 

which spring and which weights are u running?

 

Could be running a little rich. What main jet did you put in?

 

I got the clutch kit from Rick Ritter, the jet size is 160 & plug colour looks great. Once its in power band, it is great, just on take off...

 

Overheating?

 

How can I tell, its really sharp for the first ten minutes, then starts to lose a little power.

 

Sorry, havn't worked on a TB ... just suggestions.

 

Its not water cooled, & I dont think its an overheating problem, I think the clutch may be engaging at a lower rpm hot? I think a primary spring that engages higher may be better but dont know which one?

 

If you got it from Rick then give him a call. He can help you troubleshoot the problem. I'm not up on the 250 so sorry I'm not much help. I know when my 400 was having this problem it was jetting. It would run awesome for 10-20 minutes or so then kinda start losing power. It may be clutch related as well.

 

Does the motor feel like it's losing or the belt slipping? Going back to my snowmobile days, we would cool our belts before running another race and clean the clutch surfaces.