Jetting for fmf system

1 reply to this topic
  • strack

Posted February 10, 2002 - 09:36 AM


Hi Im using an Fmf hi flow header and powercoreIV silencer and was wondering what would be the best jetting for this setup. By the way i have a 98 yz400, and ride at about 1,000-2,500 feet any help would be appriciated. :)

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  • yzf_virgin

Posted February 10, 2002 - 11:32 AM


I've got the same bike and same exhaust. Change the main jet from the stock 175 to 185. The pilot screw should be set to 2 3/4 turns out. Everything else should stay the same. has all of the jetting info you could ever want.

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