backfire problems

3 replies to this topic
  • jonnyrocket56

Posted October 22, 2005 - 04:12 PM


is it okay if your bike backfires every now and then or is it okay for my 2002 YZ426F to backfire on every deceleration? also i would like to know what jets you guys us in your bike?

  • hey d00d

Posted October 22, 2005 - 05:16 PM


it could also be a leaking valve because my dad had a wr 426 that backfired every deceleration and it was a leaking valve, not exactly a good phone call when that came in

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  • 97chevy

Posted October 22, 2005 - 06:10 PM


Is it backfiring or is it popping? I thought it was if it was popping your pilot is too lean and if it is backfiring your pilot jet is too rich. Thats how I understood it but not 100 %. Have you tried adjusting your fuel screw on the bottom of the carb?

  • grayracer513

Posted October 22, 2005 - 08:32 PM


The two major causes, once again, are a leak in the exhaust system, either at the midpipe/header joint, or at the head, and lean idle mixture.

Mild decel popping, or exhaust backfire is normal and harmless.

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