New to this site but hopefully someone has delt with this problem before. 03 Grizzly 660 that starts and idles but when given some throttle it backfires and sputters like it is hitting a rev limiter. Nothing out of the ordinary happened to it, just started over night. Have tried all the usuall suspects. Any advice is greatly appreciated.

 

blown piston ring maybe?

 

did you check the spark plug?

 

Thanks for the advice guys, but I have run down all of those. I've been through the carb numerous times and looked at evrything. Compression is 120 psi with 3% leakdown so I know it is not a compression/valve issue. I checked the valves today and adjusted them back into speck. Running on empty for ideas so keep em coming please.

 

Did you test your spark as far as if it has gotten weak. Another would be to check the timing.

 

could be could be.......well it has to b something.........checking the spark/timing sounds good 2 check over see what you find

speaking of spark i bought a new NGK plug today woo!

 

Check the rubber diaphram at the top of the carb for leaks. My bet , is its installed pinched, or it has a pin hole or rip.

 

have you figured it out yet? mine is doing the same thing and i cant figure it out.

 

anyone?

 

Got plenty of gas? Tried reserve position? Cleaned the carb?