The only thing I question about AV (100ll< 100 octaine, Low leaded) gas is the burn rate of it, and the distillation curve. It's designed to burn in engines that are constantly run at 2500RPM, not around 10,000RPM. Airplanes don't need great throttle response either, unlike jetski's which (hopefully) change throttle response A lot hence, Braaaaap!:biggthumpup: . Don't take the octane rating on av gas for what its worth. It is rated differently. Normal and race gas use the RON or MON testing to figure octane rating. RON is reasearch octane number and mon is Motor octane number. I think the RON number is just what they belive the composition of the fuels octane should roughly be, the MON is an actual test where they highly stress the fuel untill they create a condition that it will detonate. American pump ratings take the RON and MON, and them together and divide by 2 to get that average (look at the pump next time you fill up!), a good compromise being the MON number is usually lower. Thats whay you see a rating on avgas like 100/130. I stay away from avgas b/c you can't compare it to race gas. Untill I know what avgas octane means in car/bike/ski fuel octane ratings I won't use it. THe specific gravity is also diff. This has two problems. First, it changes the jetting. You cannot swap between AVgas and race gas without rejetting. Because of the different weights of the fuels, your jetting will change.
Second, a lower specific gravity means it does not do as well with pre-mix oil. The oil will not stay suspended in AVgas, and will eventually separate and settle.
Bottom line is, AV gas may give you some benifit, but it's not the best. The increase in octane may prove useful if you are running a higher compression, so it is possible that you can extract more power from your engine with AV gas. However, AVgas is not formulated for high-rpm jet-ski use, and will not give you maximum performance.Sorry for the long post It just seems there are some misconceptions regarding fuels.:smile:
