Don't know if this will be of help to everyone, however seems to have everything you would need on how to maintain or rebuild a gy6 150cc motor, with specs of everything.
retired (2013 Jonway 150cc scooter 11pole stator, red racing cdi, and red coil, uni filter. 102 main 45 pilot jets. Micheline City Grip 130/70/13 tires.)