I have just purchased a 1997 Arctic Cat Monte Carlo 1000 and when i started it up it blows white smoke.?

This jet ski has been sitting inside the previous owner garge for two years before he sold it to me. He also advised me to mix the oil and gas inside a 5 gallon gas can 2:1 then into the machine don't use the oil reserve. Also should I use synethic 2:1.|||Two stroke engines do smoke white smoke after sitting for a long time.Synthetic oil is good and play it safe and mix 40 parts gas and 1 part oil or 40:1