Welcome to the forums. What does the oil look like in it? It sounds like it might still have water in the oil.I am looking to buy a 1998 450 foreman 4x4 for 1,000 it has been rolled over upside down in water and still starts and runs great but after it warms up it starts smoking grey. My ? Is, is it a good buy and can it be fixed cheaply and what exactly will it take.