WR 450 Backfiring

3 replies to this topic
  • ukuhunta

Posted January 17, 2008 - 11:06 PM


what causes backfiring on deceleration, too lean, too rich, or what....thx guys

  • gregwr450f

Posted January 17, 2008 - 11:42 PM


http://www.thumperta...ght=back firing

http://www.thumperta...ght=back firing

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • William1

Posted January 18, 2008 - 02:04 AM


LOL, both can. Too rich a needle/main can lead to excessive unburnt fuel accumulation in the exhaust. When the throttle is closed, the lean condition and heat can enabler this unburnt fuel to ignite - pow! The AIS on a WR tends to reduce the popping on a rich bike.
Also, if the pilot circuit is too lean (assuming the main and needle are spot on) this can also lead to excessive popping (the reason WR's have an ACV) Tweaking the fuel screw up to and no more than 1/2 turn can reduce it. You cannot eliminate it.

  • ukuhunta

Posted January 18, 2008 - 08:03 AM


how about a looser header pipe......just looked and mine seems to be a bit loose which could be the cause of the problem and how can i fix this, i had the head ported and polished so maybe that is the root of my evil, is there any sort of muffler rap that i could use to snug it up a bit, thx for th info


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.