dpenix76

I just got my Factory Pro kit and in looking through all the paperwork all the example settings are at sea level.I live at 2100 feet and am not sure how that will affect my jetting.I was wondering what a good baseline start would be for my bike with stock filter and Two Brothers slip-ons.Also,maybe a small dissertation on elevation relating to jetting to help some of us understand exactly what is going on in our carbs. Thanks!

mikstr

the higher the elevation, the less dense the air and the less oxygen it contains. As a result, you can count on approximately 3% power loss per thousand feet (so at 5000 ft, for example, you would be down about 15% compared to sea level). The effect on jetting then is that as you go up in elevation, you have less oxygen to burn the fuel so you must lean out the fuel being fed to the engine (smaller jets) as a consequence in order to compensate or the mixture will be overly rich.

Hawkrider

I think about one jet size smaller per ~2000 feet. That's what the consensus is on a search.

dpenix76

Is that on the main jet only or should the clips be one position leaner as well?

Hawkrider

Well, that's going to have to be trial and error. By going to a smaller main jet it lowers flow past the needle in the midrange too. So it's entirely possible that you could go with a smaller main jet and have to RAISE the needles.