just a small hint, It doesn't take much heat to loosen up an ABC piston and liner assembly " try this yourself with a set by heating in a toaster oven at 100' F . This said, anything in a rich two cycle range will NOT cause any harm to an engine of this type. As Downunder has proven beyond a doubt. All you have to do is avoid a lean condition during the first 20-30 flights. The conrod and crankpin require the mose TLC during the first dozen runs to avoid welding the crankpin to the rod bushing lower end due to lack of oil.