Follow the instructions. Pay close attention to what it says about the first tank.

IMPORTANT: YOU MUST INSTALL THE CHOKE PLATE ASSEMBLY OR THE ENGINE WILL NOT RUN WELL!!!!

I broke them (I have 3) in using 10%nitro 20%oil 70/30 Synthetic/Castor mix. Took about a gallon, first 4 tanks (14oz) on the bench the rest in the air.

I fly them all with 15% nitro, 20% oil 90/10 Synthetic/Castor mix. Fox Miracle plug is the only one I have ever used.

Be very sure you check all of the bolts and tighten them after the first 30 minutes of running. Let the engine cool first. Recheck/set the valves at the same time and be sure the engine is stone cold when you do the valves. Re-check the bolts and valve clearances after you have run about another gallon of fuel.

Good running engine. I have had zero problems with mine and have been flying them since 1996.

Dan