2-stroke and 4-stroke engines operate under different conditions, requiring different lubrication methods. The fundamental difference between two-stroke and four-stroke engines is in their gas-exchange process, or more simply, the removal of the burned gases at the end of each expansion process and the introduction of a fresh mixture for the next cycle. A two-stroke engine has an expansion, or power stroke, in each cylinder during each revolution of the crankshaft. The exhaust and the charging processes occur simultaneously as the piston moves through its lowest or bottom center position. In a four-stroke engine, the burned gases are first displaced by the piston during an upward stroke, and a fresh charge enters the cylinder during the following downward stroke.

High Quality 2 Stroke & 4 Stroke Motorcycle Oil