I had one of the older G21/46 engines that had the rotating baffle plate. I bought it to copy Jim Kirkland's install on the Mustang-X.

While it was a reliable engine, mine never quite matched my K&B .40 and OS .40-H/P engines in power when swinging 10x6/7 props. It did shine when running an 11x6/7. I equipped mine with an open front Semco muffler. Remember those? They were anodized black on the bulk of the cylinder (thin steel). Back then everyone was running flow-thru mufflers in my area. For a flow-thru, it wasn't that loud. I have found that there is a correlation between power output and volume amplitude.


Ed Cregger