I have a buddy that has a 07 wolverine 450. Its backfiring badly. Im thinking its too rich but not sure. It really backfires when you are going down hill with no power on. And now its doing it almost all the time while under power. Any thoughts?

 

it sounds like its running lean....is there black smoke under a full throttle rev? has he done any mods? i would first clean the carb then if its still running bad re-jet.

 

No. No black smoke under power. It runs fine. But just backfires. It has had no mods to the the engine. Stock. Only thing he put on was a K&N filter. Thats it. I was thinking it might be rich. He has had trouble with the carb. Twice it got something in the carb and it wouldnt run. We had to pull it off and clean out. Ran fine after that. Now its backfiring. So you are thinking Lean?

 

So am I. Look for things that make the engine lean.

 

drain the carb by taking out the plug on the bottom. Sounds like you have water in the bottom of the float bowl. Then tap it to dis-lodge any water drops.... then put your head under and suck out any remaining water... NO, just kidding.. After you tap it, put the plug back in and try it out.

 

Running lean. If he is running a K&N filter then he is able to flow more air. More air less gas. Try this, run the bike with .25-.50 choke on and see if it still backfires. More than likely it won't. Or run it with no choke and block about 1/2 of the airflow through the filter with a sock or something else. My bet is it needs to be rejetted, if he don't want to, then go back with the stock filter.

 

Thanks for advise guys. I will have him try some of the ideas. We will see what happens.