HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
heineken4menotu

backfires/shoots flAMES

10 posts in this topic

Hey whats up? I have a 98 yz400f and ever time i hit the gas then let off it backfires and shoots flames. Do you have any idea?:worthy: It also bogs when throttle is hit very fast, but not when you roll on the power

Share this post


Link to post
Share on other sites

What a great way to hold off would be passers. As long as you hole shot you should have the finish locked up.

Share this post


Link to post
Share on other sites

I have a buddy who has a WR450, if you whick the throttle when the bike is cold it will shoot a 1'-2' flame. :worthy: After it is warmed up, no problems. Only mod is a FMF slipon.

Share this post


Link to post
Share on other sites

Yes, your jetting is wrong. From what you have said so far, it sounds like your pilot circuit is too lean. You need to turn the fuel screw out. If you get the fuel screw out 2.5-3 turns and it still has this problem then you need to put a larger pilot jet in.

Share this post


Link to post
Share on other sites
I just checked the idle set screw and it's adjusted all the way in just so the bike will idle. Is it becuase its jetted wrong?

Its turned all the way in to compensate for your clogged PILOT jet!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0