I have a 2000 Yamaha big bear 400, I was riding it this mourning and all of the sudden, smoke raised fro the seat, I took that off and the smoke was coming from the air box, I took that off and there was a decent sized puddle of oil laying in the bottom, I checked the tube coming from the carburetor and it was coated in oil. I immediately stopped riding and towed it home. I asked family members and they said that I blew the motor. others said that I could have blew some rings on the pistons or even the spark plug fouled out. I took it out for less than a 5 minute ride and when I got back it was smoking again, although it didn't seem to have any loss in power and it ran fine. As of now I just need thoughts or ideas or anything that might help... I use this to haul wood for the winter and plow in the winter, yeah its a long time away but I NEED this fixed now!