There is a review of this model here in the RCU Magazine, or whatever they call it. The reviewer spoke with Kangke and was recommended to use a .91 two-stroke. He used a TigerShark engine (also a Kangke product). I have the ARF in its box, and it's next on my bench schedule. I am thinking nothing smaller than an ASP 1.08 which I happen to have hanging around, but leaning toward a TT 1.20 Pro which I also have available. If I were going to buy a new engine for this plane, it would probably be the new SuperTigre 2300 (1.4 cu in). This would be ample power at reasonable cost.

I used a Magnum .91 XLS in another Kangke product, their CAP 232 Sport (nominally a 60 size). The Extra is considerably heavier (like a pound or two) than the C232S, and presents a lot more profile drag (big fat fuselage). I did have very good vertical performance, close to unlimited, with the 91 2-stroke on the lighter plane, and I'm sure the Extra would fly OK (non-extreme aerobatics) with the same engine. However, I watched with great pleasure a GP "40 size" Extra ARF this summer, powered with a 1.20 two stroke, flying in Intermediate pattern competition. The plane carried the weight of the engine with no problem, and of course it was "over-powered," but I like all the power I can get, as long as the plane carries the weight OK.

I am not a hoverer, but I do like big verticals with no pooping out. I suppose you could get this Extra to hover on a 91 two stroke with a 15x6 prop, but I still feel it would be nothing better than OK power. I would be looking for 15x8 to 15x10 with 8 to 9000 rpm to make me happy.

You can get a few building tips from the review mentioned above, but I hope some others will report on what has worked well for them. One thing I routinely do is replace the landing gear tee-nuts and screws with 1/4" nylon bolts threaded into the landing gear mount plate backed up with an extra 1/4" thick piece of aircraft ply epoxied on the inside. I still have the occasional hard landing, and I would much rather pop a nylon bolt head than repair a torn out landing gear plate. I like nylon bolts for mounting the wings as well--same trick, knock out the installed tee-nuts and tap the holes with a 1/4-20 tap.

I think this is a heck of a good model for the money, nice looking fuselage especially, and I'm looking forward to flying it hard this summer.