I hope someone on this site may be able to shine some light on a problem I am having with my 300. I have had this bike since 2003. Bought it new. Raced it for a year and then basically just been trail raiding since. A few months ago I noticed that it was starting to miss at high RPM's. It is so bad now that at WOT it spits and sputters so bad it is really not worth riding. I have also had occasions when the motor would surge like it had a leak in the carb boot area. I have no problems at low RPM and it still tractors along like it used to. If I try and open the throttle wide open for a quick acceleration it will bog. I have tried everything I know to do and am still having the problem. The plug indicates that the engine is running lean (white tip).
I have done the following:
1) New reeds
2) New float and float valve
3) Different Jets and Needles
4) Checked and cleaned the power valves
5) New air filter and new plug
6) Cleaned, cleaned, and cleaned again the carb
I even bought a brand new carb and put on it. :bang:
My only thought now leads me to the crankshaft seal. I don't know what else it could be. Is it difficult to change a crankshaft seal and do I need any special tools? Any feedback would be greatly appreciated. This thing is driving me nuts. :coocoo:
I have done the following:
1) New reeds
2) New float and float valve
3) Different Jets and Needles
4) Checked and cleaned the power valves
5) New air filter and new plug
6) Cleaned, cleaned, and cleaned again the carb
I even bought a brand new carb and put on it. :bang:
My only thought now leads me to the crankshaft seal. I don't know what else it could be. Is it difficult to change a crankshaft seal and do I need any special tools? Any feedback would be greatly appreciated. This thing is driving me nuts. :coocoo: