FWIW, here's my latest Poulan 46cc. I've gone through a couple of different setups, and here's one that I think will work great. Terry at CH Ignitions did the conversion work on this one. I also had him special order a couple of these BCM wrap-around style Pitts mufflers. It took Bisson a while to make these two prototypes, but I'm really happy with them. They will be $99 each now for those that might be interested in getting one.

I barely had time to run it briefly on the bench today before the sun went down. 90F, 95% RH, 30.02" Hg, at ~sea level, the 46cc turned the MA Classic 20x10 a steady 7000RPM on some old stale 25:1 gasoline. This engine is practically brand new and so should yield better performance as it starts to break in some.