oil on the spark plug

[nassa76]

Got a free 50 inch mower Whit a 20 hp koler motor. when it runs you see some white smoke coming out of the exhaust. I took out the spark plugs one plug had some oil on it not good, So I'm thinking i just need to replace the piston rings on one side. Is that a big job and is it worth it. The deck is in good shape so is the frame and body. What do i do

[4.3mudder]

White smoke out of the exhaust sounds like water in the gas or a blown head gasket. If you have oil on the plug then you are burning oil, and the oil is getting past the rings.