The way I look at it, most dyno data acquisition systems say right on the printouts 'corrected torque and horsepower'. I've been told many times that these little engines do not respond to changes in air density, but if that was true, you wouldn't be looking for the right jet for your altitude. If you had an air density gauge, you could easily calculate the jet size for your area. It would be great if somebody who has an air density gauge could tell you what jet they run at what air density. The air density would have to go up five points to justify that big a change in jet size. 039' jet, that's a little more than a 5% change in area. Longacer says a 1% change in air density calls for a 1% change in fuel supply. When I raced, I considered the air density gauge a necessary item!! Even tuning them on the dyno with an a/f meter isn't the final answer most of the time for the above reasons.Д«e sure to check out the Briggs videos online, as well as the PZ tuning guide.ДЄlso.check with your local rules - There is a track out there somewhere that allows you to change the main jet to a 93.if that's the case, then you'll be starting all over again.Дў8 years of service to the karting industryДЇollow this link and read the instructions they give for using an air density gauge. For instance, we often consider the track configuration, length of longest straight, highest G corner, smoothness of track - all can have an affect on your final tune.

Realistically you will tune the engine leaner than someone at sea level, but how much leaner depends on more than just your elevation. There's a lot more to it than simply setting the floats a specific height by your altitude. 810' or so and the middle clip on your needle then go from there. AND, try your best to keep the two floats even/equal in height.ДЄs far as where to set it - you might try. Be sure to bend the tab with a small bladed screwdriver.do not bend the floats themselves. Simply bend the tab under the floats that rests on the inlet needle and remeasure.

700', I am assuming you already have a way to accurately measure float height.

Jet set go 4