9 x 7 MA 16.4 K 10%N/22%O (50/50) stock muffler
9 x 8 MA 15.1 K 10%N/22%O (50/50) stock muffler
10 x 6 MA 14.8 K 10%N/22%O (50/50) stock muffler
10 x 7 MA 14 K 10%N/22%O (50/50) stock muffler
10 x 8 MA 13.5 K 10%N/22%O (50/50) stock muffler
11 x 4 MA 14.9 K 10%N/22%O (50/50) stock muffler
11 x 5 MA 14.6 K 10%N/22%O (50/50) stock muffler
9 x 7 APC 15.5 K 10%N/22%O (50/50) stock muffler

Ski, your TS .52 sounds like a real screamer. Are those prop sizes a little small for this engine? I used to fly a TT .36 Pro on an 11x4 Zinger, which it turned very well on my .40 size fun fly. Don't you have noise issues where you fly? (Prop tip speed being a major factor.) I'm not questioning the engine, which is favorably reviewed here on RCU in conjunction with the Kangke 50 something or other.

I like them to hit their power band, our noise restrictions are somewhere around 96db. They don't bother me, unless I do something to piss them off. We fly over a closed dump, so things are not as strict, as if we were next to a neighborhood.