Colorado jetting

Does anybody have any high elevation jetting experience with a 450? I'm taking my '04 to Colorado next weekend (hopefully it will be about 40 degrees cooler than Arizona) and the guys I'm going with are saying that it will be 7000 - 12000 feet. The air box has been opened up and I have a Q on it. Currently I'm running a 168 main, 48 pj, and 4th slot from the top on the factory needle.

Thanks in advance for any suggestions.


I'm running 38/160 2nd position at 5-10,000 ft. Not sure if it is different for the 450.


You want to run 155 main, JD red #3, 45 pilot, 70 PAJ, 65 starter jet. at 80 degrees and 8,000 - 10,000 feet.

Soon as it cools down below 70 degrees run 160 main, JD red #4, 48 pilot, 72 starter jet.

Thanks for the information Indy and FTD. I'll keep an eye on the temp. next week and make a final decision then.


I have an 02 426 the with the JD kit. Would you recomend 155 for my bike as well???

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