whack the throttle

4 replies to this topic
  • humpness

Posted February 09, 2011 - 09:07 PM


I installed my Q4 and megabomb a week ago and I am having troubles with bog when i whack the throttle. It was jetted very nice up until the new pipe. I can kill it pretty easy it also has some popping(little excessive) along with it. I feel my pilot screw is tuned right(2 1/2 out).

my bike is a 07 yzf450. 48 pilot, 168 main, stock needle 4th clip

Do I need to do the O ring mod? Can I do this without removing the carb? I had a friend work on my carb a while back, I think he used safety wire before on my bike but im not sure. He also said something about a grinder also. Im hoping maybe the safety wire or the o-ring broke or came undone.

Edited by EOYZF, February 11, 2011 - 12:25 PM.

  • Yzf_Buz

Posted February 12, 2011 - 09:31 PM


Did you look into what FMF says for the are recommended jetting specs for that set up ? My 06 yz450 had to be re-jetted and I have the mega bomb and carbon 4.1 slip on. You can put a new plug in your ride to see how the carb is working but it is probably running rich with that mega bomb and it needs to be leaned out. just a guess tho, check out FMF site for recommendation.

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  • ttr250dude

Posted February 15, 2011 - 08:21 PM


jetting problem

  • humpness

Posted February 15, 2011 - 09:08 PM


jetting problem


  • ttr250dude

Posted February 15, 2011 - 10:00 PM



haha brain fart. I meant to say that the problem is likely jetting and will not neccesitate the o-ring mod. Look here for jetting.


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