Mejzlik 26-10 is what I am ran on mine. I believe it ran about 6800 or 6900 after break-in. It got pretty noisy in the air at full throttle.

Sounds like you just need some more run time on the engine. Are you ducting air through the fins. That makes a big difference for keeping an engine cool. It may allow you to lean it out some more and still stay cool.

There is a pic of my deflector plate in my gallery (click "gallery" below). Go to the DA100/CAP album and look at pic DA5 and DA2.

The air ducting I did in the cowl is also there.