Sump (wet and dry sump)

The sump is the oil reservoir at the bottom of the crankcase. In a wet-sump engine, oil drains back into the sump and the oil pump draws it from there; this is the most common layout and is simple and compact.

In a dry-sump engine, a scavenge pump removes oil from the crankcase and sends it to a separate tank, often in the frame or beside the engine, from which a pressure pump feeds the engine. Dry sumps allow a lower engine, steady oil supply under hard cornering, braking and jumps, and better cooling, so they are used on many off-road and some sport bikes.

Check oil level exactly as the manual describes: on dry-sump bikes, it is usually measured with the engine warm after running briefly, otherwise the reading is wrong.