200cc engine identification and info

[l-ovie]

Hi all
I have just recently bought a second hand 200cc Yamoto, shaft drive atv and I cannot find any info on it. From what I can gather it seems to be a 200cc loncin (or copy of) OHC??...see attached pic....what do you think?

I want to ensure everything is ok and up to spec, for example valve clearance? I have come across what seem to be conflicting specs (or me with wrong engine identifcation), .002" for both or .003" inlet and .004" exhaust.

Does anyone know where I can get service manual or similar??
Your help is much appreciated!!!