I am setting up an airboat that I'll have about $60-80 and time into, I happened across a briggs 27 or 29cc 4 stroke that I want to use for this (having a standard wet crankcase wouldn't work well for the type of planes I have), any idea on prop size? I have a 18x6 on hand, would a 16" be better suited? prop size determines how high the engine sits on this thing so I don't want to have it too high with the heavy 4 stroke. I thought the hull was a bigger project than it is, it's solid foam with a plywood deck and fiberglassed outside, little duct tape and minor touchup and it's ready other than mounting radio and engine. going camping at a decent size lake in a couple weeks, figured I'd try to get this thing going.

should be fun when I get it going