re: Got some mud motor + jon boat questions. Thinking of building one.

I agree with Coco, just get a used 2 stroke outboard. I have a 12 ft flatbottom and put a 7hp Kohler with the SPS Swamprunner kit and it ate my lunch. Never tracked straight, always had to use a lot of force to keep it straight and it was heavy. If you let go the tail wants to sink. I put a rope around the handle but still it wasn't fun. No reverse. No tight turns. Never again. I bought a 1978 15HP Evinrude for $500 and I am so happy!