I needed to convert a Cub that was just not"right" with e-power, and since the Cub was a gift from the better half, I wanted to make it "better". Did some searching, read some posts, decided I just had to go "cheap" and sprung for the RCG 20cc from HK. Opening the box was a very pleasant surprise....well-packed, shipped from US warehouse, took all of 3 days, and it was very nicely-done. Nice quality casting, double-ring piston, has the Chinese imitation-Walbro, and the imitation RcExcel CDI (this one is Paragon marked). Even came with nylon mounts that had been machined to permit a nice slim install. Couldn't believe it.

Anyway - make a long story short - got it all installed, and before first run, I pulled both the pump side and the regulator side off the carb, filled with gas, dribbled some inside, turned it over by hand a few times just to get it wet.

Choke on. Throttle at high-idle. Ignition on - FIRSTFLIPBurp. Couldn't believe it. Must have been that pre-treating.
Choke off. FIRSTFLIP running, and running very nicely. Really couldn't believe THAT.
About half way through the first tank - flip kill switch. It worked. Turned back ON - FIRSTFLIP started again - <HOT>....so I did that a few more times just to be sure it wasn't a fluke.

Normal pump gas, with Pennzoil Air-Cooled at 30:1, stock muffler, Valley View 16x8 for early running.
Am quite sure it will haul that Cub around with way-over-scale-power....

Will report back when I actually get a flight in, and update with some install pics....so far, best $179 including delivery that I've ever spent on an engine.