I tached my TT61GP today at the field.

Turning an 11x7 Master Airscrew and with a tuned pipe I'm getting 13,450 RPMs with 5% nitro in the fuel -- which I'm more than happy with.

Not bad for an $85 plain-bearing engine running on 5% fuel.

This engine has had about 8-10 gals through it and it's got so much pinch that my electric starter won't even turn it over when the temperature drops below about 55 deg F (the same starter has no trouble with my Saito 100 so it's not "wimpy" by any means.