new exhaust


7 replies to this topic
  • thrtljunky

Posted December 20, 2006 - 10:38 PM

#1

hey i just put a new fmf on the 426 but was made for the 450....fits perfect but notice more backfire on deceleration..is this the pipe or a possible valve needing adjustment????

  • Kyle Prior

Posted December 20, 2006 - 10:40 PM

#2

The pipe could be a little loose, leaking exhaust. This is likely the cause if it didnt happen before.

  • Smokeslider

Posted December 20, 2006 - 11:52 PM

#3

Did you rejett for the pipe? Pop on decel after putting on a new pipe sounds like a lean condition. When you upgrade your airflow, you'll need to jet richer to make up for it.

  • ____Kurt____

Posted December 21, 2006 - 12:06 AM

#4

run it lean and fry the motor:banghead:

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  • grayracer513

Posted December 21, 2006 - 08:19 AM

#5

The pipe could be a little loose, leaking exhaust. This is likely the cause if it didnt happen before.

:thumbsup: Check the header gasket and the mid pipe joint.

  • thrtljunky

Posted December 21, 2006 - 04:26 PM

#6

did not re-jet....header gasket and joint are sealed.....jet is stock what should i try for new jet??

  • MRD RACING

Posted December 21, 2006 - 07:19 PM

#7

did not re-jet....header gasket and joint are sealed.....jet is stock what should i try for new jet??


this can normally be cured by ritchening the pilot screw, if it does not stop popping on decel by the time you are at 3 turns out you will need a bigger pilot jet

  • 800xr

Posted December 22, 2006 - 07:43 AM

#8

I installed a white bro's carbon pro on my 06 and it popped like that. I raised the needle two clicks and installed bigger main. Problem fixed.





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