May 17, 2001
My wr250...

-Grey wire disconnected
-Airbox lid/redirector removed
-exhaust baffle removed

It runs really good but i do notice that it misses a bit... very slightly. In addition it takes quite a while to warm up... for the first 5 minutes of running.... it runs like crap (bogs a bunch) but once it gets hot it starts running fine (except for the missing)

First question... are either of these situations normal? They don't seem normal to me.

Second... I was talking to a guy at a dirtbike shop and he said with the mod's I had performed it definitely needed to have the carb retuned (jetting, clips, etc.). I am no technical guru, but it seems to me that if the bike is not running lean or rich, then the carb is adusted just fine. However I may be running too lean or rich... what are the symptoms of running lean or rich? Is there some way I can definitively tell if it's lean or rich?

Thanks for any help.


Tree Crippler

Jun 8, 2000
The fuel screw on the bottom of your carb needs to be adjusted. You should be at 1 1/2 turns if you never adjusted it. Turn it out to make it richer up to 2 3/4 turns. If this improved the running but didn't fix it all the way, then bump up your pilot jet one size. Most of the time the bikes come jetted lean from the factory. Does it pop on quick decelaration? It seems you have to keep the Yamahas at a higher idle than most bikes.

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