BRP High Altitude Jetting [Colorado]


I have a 2000 XR650r and we recently moved to the mountains.

Riding altitudes here are from 8500-12500 typically.

When we get up to the higher altitudes the BRP doesn't want to start, and takes a rolling gear engagement to get it going. I'm suspecting it's way rich.

Any suggestions on jetting?




Hi. I also ride a lot in Colorado between 8000' and 13000'.

I use the following jetting on my XR650R for those altitudes: 155 main jet, jet needle at 3rd clip

position (middle setting), stock pilot jet, stock air screw setting.

This jetting setup works only if your bike has been properly "un-corked". If the bike is not un-corked, or is un-corked incorrectly, the settings I give won't work. Make sure the bike is properly un-corked, and use the settings I show, and the bike will run very well at high altitude.

My bike usually starts on the second kick when warm, at the top of engineer's pass (around 13000'), so I know these settings work well. Have fun!

L.L. Buena Vista, Co.

Hi LL,

Thanks for the information. Yes, my bike has been un-corked with the OEM components. What exactly is the stock air-screw setting?

BTW...I live in Silverthorne and ride the BuenaVista area from time to time. My email address is

Last weekend...



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