pbf engine.
Planebender,
I am happiest using a 9X4 MA prop. My Norvel is OK with it and the OS loves it. We have run down to 8X4 props on both with great success. Have never seen an OS get hot and die unless it is too lean. Every flight has the potential to go through the full tank as long as you don't get too wacky - haha, yea right.
Dale