250r engine dies in powerband

[250rwrx]

i just rubuilt my engine with everything new and broke it in properly, when i take it for a ride it runs great but sometimes when im out on the road it will run great through the powerband then all of the sudden when the powerband kicks in it dies if i let off the gas it will idle and run slowly but when you hit the gas it dies. if i stop and let it set for 5 minutes and restart it with a lot of kicks kinda starts hard but then it runs good no problems at all i have no idea what is causing this.

[gogoquadzilla]

sounds like your main jet is way off. you probably need to step up a couple sizes since you just rebuilt. did you bore it out or do any porting?

[250rwrx]

no its the same as before i rebuilt it it ran good then all i did was install a new piston and rings and a new powervalve. if it was the jets wouldnt it do it all the time not just sometimes, would overheating cause this?

[ONLY2STROKES]

overheating may be a prob..i would check all gaskets for a possible aireak.this will cause it to run lean and do some serious damage and overheat.did you use stock thickness gaskets,just an idea may have raised the compression with a different gasket.

[250rwrx]

i used all original gaskets that i ordered, i went through and tightened all the bolts, and it still does it sometimes, i have a lrd adjustable exhaust would that cause this?