I had a Quadra 75 in a 1/4 scale ME109G and with a Bolly carbon fiber 21x12 it would turn about 7300 on the ground. I would expect a Menz 22x12 to be a little less than that, perhaps around 6800-7000.

The drop in rpms is interesting. I assume that he carb has been checked and that it is tight on the engine? It sounds like it is heat related if it doesn't do it until the engine gets warm.

-Ed B.