I picked up a 1997 GTX with 175 hours. It ran okay but it kept popping the rave valves off it was either the bellow would come off or the cap was busted in the meantime I added one quart of Evinrude XD100 oil. I read everything on the bottle and it looked like it meant the specifications of the Sea-Doo.... I probably know better now. I finally got the Rave valves fixed but now I have white smoke out of the exhaust it'll run like a champ for about 3 minutes but after that it cuts powered about 40 mph and sputters. Is this a wrong oil issue or do I have something else going on.