Wanting Zongshen 250cc engine service manual or how to set up timing would help.

Needing Zongshen 250cc engine timing help and/or page(s) from service manual . My single cyl, air cooled, 4 stoke, factory case stamped ZS169FMM, * 89700102*, installed in a 2009 giovanni X-31 dirt bike. I was not as careful as I should have been when disassembling, now in need of help please. 1st issue -The upper timing chain gear can be bolted to camshaft in two different spots (180 degrees apart). Camshaft mount has two threaded hloes and gear has two drilled holes , holes are not off-set and unfortunately there is no master spine/keyway or the like to make its mounting idiot proof ) and I'm not 100% that I have the mounting to the camshaft correct (50/50 chance). On the outward face of this gear there are two stamped in lines radiating outward from gear's center, 180 degrees apart. Also stamp on same face is a Z and about 180 degrees from it is FL. Once I find out how to properly mount the gear to the cam here is my next problem - I assume one of these marks/identifiers(the F or Z or the lines) is to aid in valve timing set-up but i don't know which mark to use and also what it is to line-up to/with. ALSO -on the lower end timing scene - there is an F then T (about a 1/2 inch apart) stamped in the metal Drum part (can't remember proper part nomenclature) that spins, has magneto magnet mounted to it and surrounds the charge winding. This Drum has a bolt connecting it to the crankshaft, anyway, on the Drums cover there is an access hole to get on this bolt to spin the crank and also a smaller inspection hole above it with a slight notch in the top of the small inspection hole. The engine is at TDC when the T on the drum part is lined up with the notch in small access hole. I would greatly appreciate any help in properly timing this engine. I'm a 55 year old heavy duty mechanic, new to computers so hopefully if I figure out hope to post this message that I'll also figure out how to access any replies made to it . Feel free to give me any guidance on that issue also. Peace-out and Thanks