how much decel popping is normal?

3 replies to this topic
  • humpness

Posted April 24, 2008 - 02:09 PM


I have been reading past posts and have learned a lot! I bought a 07 yz450 a month ago. I love it. The question i have is that it backfires quite a bit at decel. How much is acceptable. I also dont get it started when cold until after about four kicks. Idle is steady. every thing is stock.
UNI filter(clean), 160main (stock),1500-3500 altitude(eastern oregon),
50-100 temp. air screw set at 1 3/4-2 turns.

any suggestions much appreciated.

  • William1

Posted April 24, 2008 - 02:19 PM


Twist the throttle once or twice before cold starts, giver her a few squirts.

Open the fuel screw some more, that will often reduce popping. No more than 2.5 turns though.

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  • grayracer513

Posted April 24, 2008 - 03:32 PM


When it pops a few times on decel 1/2 to 3/4 of the time, that's about right. Look for an exhaust leak before you monkey with the carb.

  • corndog67

Posted April 25, 2008 - 09:02 PM


I went to a 48 pilot, I'm at sea level, maybe a couple hundred of feet altitude, and it eliminated about 90% of the popping.

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