Oil filter

The oil filter removes metal particles, carbon and dirt from the engine oil before it reaches bearings and other close-fitting parts. Most motorcycles use either a spin-on canister filter or a cartridge filter inside a cover on the crankcase. Many engines also have a mesh strainer on the pump pick-up.

A bypass valve lets oil flow around the filter when it is clogged or the oil is cold and thick, so a neglected filter means unfiltered oil, not no oil.

Change the filter as the manual says, usually with every oil change. Use the correct filter for your model, lightly oil the seal on fitting, tighten by hand or to the specified torque and replace cover O-rings. After starting, check for leaks and recheck the oil level.