Rotax 80 vs 100

[louie928]

Hi,
I'm contemplating getting back into flying after a few years off. The Kitfox seems a good choice for me. I found this forum and this is my first post here. I've seen used Kitfox planes with the Rotax 912 80 hp engine. I suspect the 80hp engine has lower compression ratio as compared to the 100hp. If so, is there a problem with using 100LL fuel? Any other conditions with the 80hp I should be aware of in choosing a plane with this engine?

Thanks.

Louie

[Av8r3400]

100LL is not the best for either of the 912s. It will work if you must, but these engines were designed for automotive fuel, 87 octane minimum in the 80hp 912UL and 91 octane minimum in the 100 hp 912ULs.

If you need to run 100LL (During a x-country if auto fuel is unavailable, for example), both LEAF and Lockwood recommend mineral (non-synthetic) oil with a maximum 25 hour oil change interval and a lead scavenger in the fuel.

[louie928]

Thanks very much.