6 or 8 horse longshaft 2 stoke. Ive used both on my boat, the 8 wasnt any better then the 6, you can only go so fast.

IMHO the BEST motor for trolling is a Mercury ML8 2 stroke. Its as quiet as most 4 strokes and 1/2 again as light. And with the shifter in the twist handle its the best for one handed operation.