Just ran this engine this weekend on my new Cap232.
Bisson muffler had on hole plug by previous owner. Was very quite and tached about 7800rpm on an 18x6 w/Zinger on 15% Ritches brew and Perry/pump/carb tnak on C.G. Ran very smooth and predictable. Would run much harder on higher nitro, but all have is 15%. I unplugged the hole and gained about 250 rpm just a little louder but acceptable. I will try different props. 18x8 Simitar series is supposed to be a good one. I am also going to try a 18x6-10 for grins.

I now have a Zinger Classic 18x8 wide blade if someone could use it.... $10... I will mail it to you. Just wont work with this engine.