I must be missing something on the 4-stroke issue. When I read the Saito specs, the .91 only delivers 1.6 hp. Maybe torque is the issue.

It looks like I should be in the .76 2-stroke class or greater.

Ths GMS .76 @ 2.5 bhp and $100 looks good. That is if GMS makes a decent engine.

Cost is an issue so if the GMS is not a good choice maybe a Thunder Tiger or a Super Tiger would do.