For 25 bucks I can't be wrong

16 inch is just fine. I'm sure it will have more than enough power than I will ever need. It is scale model of the plane that can't even make loop or roll. The narrow wing and slotted flaps shuld make stall speed low. I'm sure it will fly. I was thinking about bigger prop just because of the scale look, but if I have to live with 16 inch - I will.

I just weighted the engine again this time without the prop (and no muffler - should arrive any time). Exactly 3 lb 4 oz. Muffler weights 4 oz, so my setup is the same as other guys have. I still can cut off the old fuel tank mount and save 1 oz.

Here are the pictures of the mount. You can see I didn't use the old fuel tank mounts. I still keep them just in case. But when I see my mount doing fine while engine is running, I will remove them.

RysiuM