This has basically all you need.
http://www.johnnypag.com/motorcycles...vicemanual.pdf
Those Lifeng bikes all have an engine that is based of the Honda 233cc parallel twin.
You could get a Haynes and Clymer for the 250 rebel/nighthawk and it would be good for reference.
This is the sales network…
http://www.regal-raptor.com/eng/sales.asp
So obvious inside of that are people that can support that bike, get parts and provide specifications if not actually do the work.