I have a Poulan 42cc on my Giant Big Stik. It pulls it straight up after about a 20' take off roll. I believe the plane weighs about 13.5 lbs.

I think the 40cc is of the same design as I also have a Poulan 36cc that looks identical to my 42cc. If it is like mine, it is very easy to convert, but you will need to either put electronic ignition on it, or use it as Gas/Glow like I did mine. The ignition parts are in the saw body; not mounted to the engine. One thing I do like about it is that unlike the commonly converted 46cc model, you don't have to make some sort of a carburetor mount. The carb mounts on a phenolic spacer like most engines.

The pics shows how I mounted mine and I have had no problems with it after a year of flying, but it is more common to make aluminum side plates that bolt to the crankcase bolts, and then bolt to a standard beam mount.

AV8TOR