I believe it might be a 42cc engine. The 46cc Poulan engines had a round, spigot type carb mount.

It would probably do well with a 20 x 8 prop or equivalent. The engine is a bit heavy, but runs well. I had one on an 80" wingspan Giant Stik several years ago and it flew quite well.

To check displacement, measure the bore and full stroke. Then use the formula (bore x bore) x stroke x .7854 to determine displacement. If you measure in millimeters, divide the result by 1000 to get cc's.

If you're careful, you can measure the piston stroke by going down through the spark plug hole. You can roughly measure the bore by sticking a pencil in through the exhaust port and against the far cylinder wall, and rotating the crank until the piston makes a mark by pushing the pencil up against the top of the exhaust port. That gives you the two measurements you need; the formula will give you the displacement. It's rough, but it will get you close, and you don't have to disassemble the engine to get the displacement.

AV8TOR