I also had the same problem.My local dealer was out of oil,they said Suzuki was testing their oil and they would not have any until April.Sorta makes me wonder what was wrong with the oil I had been using.They are also a Tohatsu dealer and they tried to sell me that oil in place of Suzuki oil as that is what they were using in the shop.(don't know if they were telling customers or not) Anyway,as long as the oil meets Suzukis requirements they said I could use it. I used Quicksilver 4-stroke oil I picked up at Academy.It was 6.50 a quart.