TXEasyrider

Don't know a lot about Jet Ski's but think my issues are minor. Just need some help troubleshooting. The ski is a 98 1100 STX and it was not running when I got it. The owner who gave it to me told me he thought it may have been rolled and then rolled back the wrong way. He pulled the plugs and cranked it till all the water came out of the cylinders. fired it back up and it ran like a perfect for about 20 minutes then it started smoking white smoke from the engine compartment. he shut it off immediately and put it on the trailer. Now what i have done. replaced the battery, starter solenoid and fixed a couple broken wires. pulled the plugs, sprayed wd-40 into the cylinders, cranked it by hand to make sure it was not siezed and then cranked it with the plugs out. no water came out so I reinstalled the plugs and started it. The white smoke was actually in the exhaust but the exhaust hose was disconnected inside the engine compartment so it looked like it was inside. the ski idles good, and appears to have no issue other than this thick cloud of white smoke that also seems to have oil in it. Plugs are wet with oil. The previous owner was there when I started it and said it sounds just like it always did. I don't have a lot of money to waste letting a shop troubleshoot this so can anyone tell me more of what I should be checking and if there is anything I can do without sacrificing an arm to fix this thing. He also gave me his 2002 1100 STX DI and a double trailer...both have minor issues but I have that under control. Please, somebody help me out here...my kids can't wait to get on the water.
I would also like to know how and where to install a water outlet to run both ski's on the trailer to clean out salt water or troubleshoot any problems without the risk of overheating and seizing up the engines.