Cheech:

Far be it from me to bust your bubble, but you aren't going to be able to get the engine rich enough to keep it from overheating and still develop any amount of power.

First fly the plane with the cowling off to be sure there's no other problem.

From there I see only two options. First, preserving the good looks of the plane, is to install baffles to force the air around the cylinder before it goes out the bottom. At the moment the air flowing in the front and out the bottom is not going around the engine.

Alternately, open the glow plug access hole up to about a two inch diameter. Since that really may still not be enough, I'd try the baffles first. You may have to do both. Hope not, looks too good as it is.

Bill.