Shooting Flames!!!!!!!

Help! My bike is shooting foot long flames out of the tail pipe along with a loud backfire. i have a 00 426. Any input??

Pull the spark plug What color is it?

The spark plug is brand new. It happens when I chop the throttle off.

Backfires are usually caused by a lean mixture, Im pointed at the carburetor, have you looked at the sediment bowl in the bottom of the carb unscrew it and see how much junk is in there .You may want to just take the carb off and clean it.

Man, there have been a few times I could have used that problem when some 2 smoker came up behind me...

MAN! get a picture before you fix it!!!!! I'd like mine to do that! Gotta look pretty cool!

Doesn't it say in the manual not to chop the throttle when you start it? That might be part of your problem?

Try this link it's not specifically for a YZ but you might pick up some tips there, hope this helps:

Backfire Solutions

If it looks like this on a car


it must look awesome on a bike :)

[ November 23, 2001: Message edited by: Psycho426 ]

It does look pretty cool, but the doesn't solve my problem! The Carb is clean. Just did it. Any more suggestions?

Is the sediment bowl the plug on the bottom of the carb?

In the UK if a 426 back fires its because it has standard unleaded instead of super unleaded.


The guy's a FMF reckon you want ajdust the screw under tbe bowl by a turn or .5 to 1.5 turns

good luck.

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