For parts, try Hooper Imports...they specialize in Lifan parts which in 2007 was pretty much the model from which seemingly many of these bikes were made from, or these companies manufactured bikes for Lifan under contract and also sold them under their own name ; i.e. HiBird.
Www.hooperimports.com
Also, because I have befriended them and they are a distributor with many Chinese contacts (besides just what they carry) is Excalibur Motorsports.
www.atv4usa.com 909-591-8800 as well as a 1-800 number on their site somewhere...