There are so many older, used engines out there that it's a shame not to rescue them.

I did some preliminary runs with a Mac's muffled pipe. The header is at the stock length. I'll cut a 1/4" off and try again.

Same fuel and prop as before
13,761
1.67hp
8.97lbs. static thrust

This pipe is way, way too loud to run any more on my patio. I'll have to wait until the weekend when I can set up down at the local school.

David