[Guest]

Backfiring when lettting off of throttle, I have changed spark plug, cleaned air filter, cleaned spark arrester, removed carb. cleaned it, tightened muffler where it ties to pipe, cleaned gas tank put in fresh gas, problem is not as bad but still does it sometimes when letting off of throttle, please help. Thanks.

 

[foreman lover]

Sounds like it is running rich, mine did that when I had the wrong jet in it, I put in a smaller jet in and now its ok. Have you played with the jet, needle setting, or A/F mix recently? What if any mods do you have? does it backfire only after a high speed run or at any time? A list of mods and jet, A/F screw and needle setting etc will help alot.

 

[Guest]

The backfiring starts after you ride a few minutes, then when you accelerate and let off of throttle it backfires and sometimes under downshift it backfires, have not adjusted fuel mixture, I do not know much about adjusting carb. I bought the Atv used a few months ago , not sure if it has stock jets or not, do you have part #'s by chance for factory jets and needle. My atv is stock except for 27" Vampires and a highlifter lift kit.

Thanks for your help..

 

[dirty4man]

the stock jet for the foreman 450 is a oem#130, I am not for sure on the needle. from the factory the air/fuel mixture screw should be around 2.5 turns out and the e-clip is usually set in the middle notch of the needle.