99 WR400 O-ring for seat in carb?

3 replies to this topic

Posted April 25, 2008 - 08:52 PM


Twice now I've put fresh fuel in my 99 WR400 at the beginning of the riding season and fuel runs out the over flow tube. The first time I bought the needle and seat assy. $$$. But the second time I noticed the needle still looked new, so I figure I would try the o-ring on the brass seat. It's just my luck Yam. does not sell the o-ring separate, you have to buy the complete needle and seat assy. To much $ for just the o-ring. After doing some measuring I think the o-ring is a 9mm I.D. x 11mm O.D. w/1mm cross section or width, Viton material. Can anyone verify these dimensions before I give McMaster-Carr $6.85 for 25 of these little guys? I'm hoping the Viton will last longer than the Buna factory o-ring.

  • bg10459

Posted April 26, 2008 - 05:49 AM


Can't help you there, but have you checked the float height?

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Posted April 27, 2008 - 08:07 PM


Yeh, it's o.k.. Thanks for askin. I hope maybe someone into jetting or someone who deals in these carbs would know.

  • William1

Posted April 28, 2008 - 03:06 AM


I think Sudco sells them, Carb Parts Warehouse. I read another thread that a Polaris snowmobile uses an FCR and sells the oring sperately too. Time for siome teleophone sluething.
Exact size is not super critical but if you are not close enough, you will have problems. Make sure you get the seat fully pressed back into the carb body though.


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