Blended 100LL/Unleaded Fuel & Oil Change Interval

The answers for this are found in the maintenance manual line.  Mogas, 100 hour oil change.  Avgas 50 hours.  The total exposer to lead between oil changes is up to 30%, more than that then you have to treat it like 100% Avgas.  Put another way, fill up 10 times, 7 times Mogas and 3 Avgas then it is the same as all Avgas.  If you just splash and go a few times no problem, run the oil change up to 100 hours.  

There is no 25 hour requirement, except initial evaluation,  however many recommend that you lower the oil change times if you are doing flight training where you have a lot of touch and go flights.  That requirement was removed a long time ago from Rotax.

Cheers

Thanks!