Yeah, the Poulan 42cc is heavier than the 46cc, but it is a good engine none the less. If I remember right, the exhaust timing was a bit short on mine. 150 degrees is a pretty good all around exhaust duration number.

I flew the hell out of mine, and had no problems. I ran mine on Gas/Glow. It pulled my Giant Stik around with a lot of authority. I'm talking 20 to 30 foot take off rolls, and then vertical or nearly so! My brother conned me out of mine, and it is going to go on a 78" Edge 540. I expect it will do fine...

Probably a 20 x 6 or possibly a 20 x 8 would be a good prop for your application.

Enjoy,
AV8TOR