I just bought a seadoo, the guy said it was a 1992 gts, but the plate on it shows a 5811 which appears to be a 1991 GT 10' the motor is colored yellow, on the exhaust side of the upper crank case there is a 2 port return line which the gts manual doesnt show. There doesnt seem to be any service manuals for a 1991 GT that I can find. Help!