The man at the Local Hobby Shop told you the truth. He may have been more helpful and attentive than you thought?

Some other options you may have is to put a fan on the engine to keep it cool and to give it some load but I wouldn't want to be around a homemade fan that is turning 30,000 rpm.

You could also put some electrical load on your generator. That in turn, will load your engine some.

Enjoy,

Jim