The old K&B 8011 and 4011 engines. The 8011 had a rotating baffle, and the 4011 took the K&B muffler. MECOA might still be building some new ones. You can find them used almost anywhere. Swap meets are a good place to start. A lot of them will be burned up, because they didn't take misuse or abuse very well, so look them over carefully. I've got several, plus some parts. The best modification I did to mine was to adapt a Super Tigre 40 carburetor. Over the years K&B used several carburetors. A couple of different Perry's,Irvine, and an in-house carb, but most were marginal, compared to modern carburetors. These engines have a bolt on front housing that can be rotated to 4 different positions. To reverse the engine, rotate the front housing 90 degrees. Any brand engine with a bolt on front housing should work. Some engine manufacturers make left hand rotation crankshafts. Good luck, Greg