Thread: Jetting 101
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Old 30-11-2006
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Keg Keg is offline
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Join Date: Apr 2002
Location: 2 Stroke Town
Posts: 9,942
Altitude and Temperature

These two things effect your jetting and it is worth considering changing your jetting atleast twice a year to get the best power out of your bike (start of summer and winter).

As you go higher in altitude the air gets thinner, which means your bike runs richer, so often you have to compensate by leaning your bike out when riding in the high country.

As the temperature goes up the air also gets thinner and your bike runs richer, so your fuel needs to be leaned off also.

For a starting point for this adjustment, try leaning your pilot by turning your mixture screw (air screw for 2T and fuel screw for 4T - see above post) about 1/4 to 1/2 to see if the bottom end response improves. This can be done on the trail, but just remember where you are at with your settings.

If you get real keen and think the mid is too rich try raising the clip on your needle one position to lean it out. I will discuss plug colour to check how accurate your jetting is.

Lucky Victoria
Now if you live in Victoria you are lucky because although we have some good high country the higher we go the colder it generally gets which means the air density does not change drastically and only small adjustments are often needed.
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