WR400 Carb

4 replies to this topic
  • giants922003

Posted May 29, 2007 - 10:51 AM


Bought a used seemed to be in descent shape 98 wr400. bike was cold and started up on the third kick. The rpm's seemed to bounce around, assumed from being cold. Ran the bike and it's strong. Replaced the air filter (twin air), new plug and the bike pops off, but won't stay running for over 10 seconds. So I yanked the carb off, and the jets are all over the place. The bike has white brother e series pipe. Main jet was 165, pilot jet 85, starter jet 70. Accel pump rod is rusted along with the metal around the diaphram. I have all new oem parts on order.
This is just a starting point to try and tune the carb in, any other suggestions would be helpful and is there anything else that may cause the bike not to stay running?


Posted May 30, 2007 - 11:35 AM


check the jetting database. there is lierally a TON of jetting combinations:


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  • SXP

Posted June 02, 2007 - 11:53 AM


pilot jet 85,

That's nuts :thumbsup: Should be in the 45 range.

  • Oasis_Flame

Posted June 05, 2007 - 09:37 AM


Yep, your pilot jet is way to large for starters. Go back to all factory settings including air jets and start from there. The carbs are easy to tune but you need a good base line to work from. I'm all stock setting except the main jet which is a 162 at 4000ft. Clean the carb up very good, sounds like it needs it.

  • giants922003

Posted June 05, 2007 - 11:21 AM


That is my plan, parts should be in today so I can get started on it. Let yall know how it goes.


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