Mercury - Full Synthetic Motorcycle Oil 10W-40 4-Stroke Lubrication Full Synthetic 8M0060085. Overview. Any rider who's spent time on winding backroads or hot summer highways knows how much trust we place in the oil running through a motorcycle's engine. It's not something you think about when everything's running right - and that peace of mind is exactly what the Quicksilver 10W-40 Full Synthetic Motorcycle Oil (8M0060085) delivers. Whether your bike sits for stretches at a time or sees regular