RE: GMS 47 engine
The Tower engines are the same as GMS from what I hear.. All of mine were the same way. It's the ABC construction and it's fine. You can expect it since it's new. After you break it in real good it'll be smooth.
I didn't even use a heat gun. Just prime the hell out of it and fire it up. Shouldn't even need a starter...
My 2 cents....