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Thumper 270X jetting for Colorado 400

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After a year with the 270, an 06R head and opened air box - I'm still figuring mine out, so I'll be very interested in seeing other 270 owners' responses. In the meantime, here's what I know:

1. "Colorado" has a lot of different meanings depending on where you're riding. You can easily get 5,000 foot differences in elevation between front range and mountain riding locations - so take that into consideration before jetting.

2. Rick Ramsey has done the most work in this area - although his chart is for a 250x (rather than a 270), you can still use it as a pattern/relative guide and move up as you fee fit:


3. For 8,000-10,000 (70 degrees) I'm running 150/42/2nd clip/2 1/2 turns - which you'll note is substantially richer than Rick's chart. I'm more concerned about running lean than rich, and some rides will run from as low as 7,000 feet.

Good luck.

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