Do you have non ethanol gasoline available to you?
I use that in my KF2 all the time and keep about 40 gallons in the hanger ready to go.
I attached a page from my O & M manual for my engine. It is not a Rotax engine, nevertheless is good information that applies to similar engines. I underlined what it says about leaded gasoline.
They also talk about gasoline with alcohol. I traps water if you let it sit. If you fly all the time that is not an issue. Just make sure your hoses, gaskets and sealants are rated for alcohol since alcohols are very aggressive solvents.