I assume that the Changchai is a Changfa knockoff. I have read horror stories about some knockoffs and wondered if mine is one of them. It is connected to an 8 KW Stamford generator, the genset has not been used much in the 9 years since I bought it new from Hardy. Does anyone have any info on this set good or bad. Also the book says to use water in the cooling system. Mine has a radiator and fan, can I use anti-freeze? I know thats a stupid question but thought I'd ask anyway. Any info is appreciated. Thanks Joe