I have a P.A.W. 40 with the Varijet carb. I used it to break in the engine, and it seemed to do just fine.

(I subsequently took it off in order put on a control line venturi and needle valve assembly.)

I also have a P.A.W. 19 single ball bearing engine with the old square "primitive" carb mounted on a Texaco model which I fly just for fun with a throttle. The carb seems to work pretty well.

Good luck with your engines, Dzl