Thanks,

There was a good article on tunning on www.raptortechnique.com

Power will go away if it getts too hot. Helis really don't tune the same as the planes do (i'm a former planker too) you have to run them ridiculously rich to keep them cool enough.

Does the engine still have compression? Do you have someone experienced to help out?

If you decide to change the engine, have a look at the Irvine 39 (will drop in place of the OS 32) or if you can get the right gearing and mounts, the OS 50 runs cool, is a breeze to tune, and provides tons of trouble free power. It took a while for me to get my TT39 going, but the OS 50 was just drop in and go.