The implication that anything over 5% nitro content will cause problems is simply absurd.

There is a lot of specuation and very little info here only vague referrences to "yelling at hobbico" and shipping airplanes back, mid airs and crashs. Does Tower insure crash damage of their engines? seems unlikely.

I would want a lot more info before I made any more recommendations beyond leting someone local in his club who is experianced with engines look at it and then make a decision as to what he should do.

Calling hobby services up and yelling some more is not going to accomplish anything.

John