That's interesting. So far, everything else about this engine is superb: Great power, fit and finish and easy starting, so it's a funny little wart on an otherwise spectacular engine.

I picked up the tuned muffler and that works REALLY well with the engine. I've broken the engine in with that and it pulls very nicely. So, I'm going to run that combination to start. I just need to get building something to fly with this engine! If I wind up needing the quiet muffler, I have put it back together with gasket sealant, but I have not added more rivets. I will see if it loosens then I'll add rivets as needed to keep it together.

Thanks for the info!

John