I have a Yam 50 autolube, my question is, is there any difference between the 2 stroke oil I put in this to the 2 stroke oil used in motorbikes? I know that the marine one I last bought was fully synthetic, but it was very expensive. I can get motorbike oil for a fraction of the cost, (father in law owns motorbike shop). Has anyone used motorbike oil in their outboards? If so was it OK?