Some ideas on jetting for a 99 wr400

2 replies to this topic
  • Guest_Guest_*

Posted August 22, 2000 - 03:19 PM


my wr is all stock except for the baffle is out, I live in western PA. I'm just looking for soom info on jetting to max out the power and performance on my bike.. has a dead spot on the crack of the throtle.. and builds rpms slow...
all post will be helpful

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  • littlerm

Posted August 23, 2000 - 05:30 AM


I have a '99 with the stock exhaust with baffle removed, airbox lid removed, and YZ timing. I use a 178 main and a 48 pilot, stock needle, stock clip position and it runs terrific. I never have any starting problems, either. I ride in middle TN and north AL, I think the elevation is 500-1000 ft. Hope this helps.

Roger Little
'99 WR400

  • TW

Posted August 23, 2000 - 10:16 AM


Your jetting is all going to depend on time of year(hot, humid, cold, dry variables), altitude, what mods you have made. Your hestation may be caused by a dirty accelerator pump, clean it and see what happens. Also count how many turns out you fuel mixture screw is and write it down, then try 1/4 turns out and see if it clears up the hesitation. I am currently running two turns out on the fuel screw and have all but eliminated the hesitation, of course this is just one variable, and each bike may be a little bit different.


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