Konrad, are you actually flying with any of these or are you just using electric stuff?

I've never seen them as nothing but mild sport engine and I'm getting about 14500rpm on the RC version (if I remember correctly) on a 7x4 MAS and 10% nitro, 20% castor. I have tried 0% nitro too but the compression ratio is a little low and there is no low end adjustment on the carb either, it runs but misses a little.