So I bought a 2004 Yamaha Big Bear 400 4x4 a few days ago. Just ran it out of the gas that was in it, and put some new gas into it. Well, the quad had a couple small problems which I tackled, however, this one I didn't see when inspecting it. Just now I started it up and it billowed out white smoke and it smells very strongly of oil. I have almost no doubt that the engine case is cracked or the head-gasket is blown. I checked the oil level, and sure enough there is barely any left at all. I wanna known if this is what the son of a bitch did to me. Can you add something to fuel (Don't say any specific names, I just wanna know that it can and has been done) that will hide the fact that oil is getting into the engine?