I have inherited a rear exhaust K&B engine with 3.5 on the crankcase. The engine also has a black carburetor and what looks to be a Mac's header installed. The number on the left mount flange is A0019893. I assume the 3.5 is "cc" and that would mean it would convert to .21ci. Is that correct?
I know nothing about this engine, and would like to get information on it. I would guess a 9x6 prop would about right for the engine on a relatively docile plane like a small trainer. I will probably sell the engine, but I don't know what kind of fuel to recommend.
Harlan