Small Engines (Lawn Mowers, etc.): white smoke on start up, john deere lx, dirty oil

Question
John,
    Thanks for your time. I just purchased a john deere LX 279 with 535 hours on it. It has the two cylinder Kawaski engine. When I first tried it before buying it, there was virtually no smoke at start up. None once hot and running. I brought it home, changed the very dirty oil and filter, and now...a big blast of white smoke. Only when it is cold. Only when starting it. Once hot there is no smoke, plenty of power and no running problems. The spark plugs are burning powder grey, with no oil fowling. Tell what's going here and the best way to fix it...or at least what to look for next. I'm pretty handy! thanks!   jim

Answer
 Hello Jim:

 Check the Oil for a Gas Smell. If you will Send me the Model Numbers Off of the Engine, Please. With these Numbers I May be Able to Locate a Breakdown of the Engine and Better Assist you. The Engine could have a Collapsed Oil Ring Also. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John