White smoke from my lawn mower?

I have a Sears Craftsman 4.5 lawnmower, model #917.388040. It's almost 2 years old. I was mowing my lawn and suddenly a lot of white smoke started pouring out of the left side of the mower. It was so bad my neighbors came over because they thought it was on fire. I shut it off and noticed oil on the front of the mower. I know it's not the oil filler because I just replaced that. My neighbor said it might be the o-ring and if it is, I might as well buy a new mower as it costs almost as much to replace this. I can't afford to buy a new mower right now. Is there anything else I can do? Thanks in advance for any help you can offer me in this matter.