I've never stored a motorized bicycle 2 stroke engine but when I was into R/C planes we used to make sure all the fuel was out then put ATF, automatic transmission fluid, in the crankcase and cylinder if the engine was going to be unused for a lenght of time. The ATF would keep things lubricated and prevented corrosion and rust.
I would have to assume the same would work on a China Girl or a 4 stroker.
Tom