Questions about using 426 jetting on a 400

1 reply to this topic
  • Jimmy_K

Posted October 02, 2001 - 06:57 PM


I read a post about using a 426 needle in a 400 carb for better mid range. I have a 99 and I am interested in the details of this setup. Clip position, main jet, pilot... I live in wa state apprx 2500' elev. Thanks

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  • James_Dean

Posted October 02, 2001 - 08:36 PM


Try the '01 YZ426 jetting with a few variations.

#45 pilot
1 3/4 turns out
OBEJN needle, clip #3 (richer option)
#168 main jet

You will feel a major increase in mid-throttle power. The stock DVR needle is lean in the mid-range.

See: and look at the 4-stroke needle graph.

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