i'm having this problem with the low end running rich, no steady rpm at like 1/4 to 1/2 throttle. just rejetted for my pipe and air filter, running a 154 main and 42 needle jet, top end jetts in dead on but i can't seem to get the low end to come around. All help is greatly appreciated. thanx

 

The needle jet circuit controls the fuel in the 1/4 to 3/4 throttle position. Try dropping the needle one position from where it is now. It is normally in the 3rd position unless you have raised or lowered it.Install a new or clean plug & test ride at that same throttle opening & stop & read your plug