Was out on a ride today and the bike was running fine for about an hour then the problem started. The engine would not rev up past 5600 to 5800 rpm, it would only sputter and not make any power.
The bottom and mid range power was fine but the rpms seem to hit a wall and thats all it will do.
I changed the plug and it was not to bad, mostly tan with a little blackish here and there, I put a new plug in and had the same issues as above.
Any ideas, I'm going to tear into her tonight[img]i/expressions/face-icon-small-smile.gif[/img]

 

Your air filter might be dirty have you checked it?

 

It has a clean K&N air filter,

 

check your carb hose i forget what its called if that is loose it will draw in air and cause your atv to act like u stated above