Need jetting help on 2000 Yamaha YZ250

[Derryl Leverett]

Next saturday I'm riding in the mountains at about 5500 feet. My bike is jetted for 1000-1500. I rode up there last month and the bike ran terrable. I have a FMF gnarly pipe, eric gore low end porting, and v force reed cage. I'm currently running clip position #2, 172 main, and #48 pilot jet, air screw 1 1/4 turn out. I hope someone can help me before next weekend.

 

[02yz125]

Derryl, I would call a dealer in Colorado, Denver area, and see what they jet there bikes to stock. Most dealers out there jet for the altitude. You might have to go a tad richer because of the pipe. But at least it will give you a base line. Hope this helps.