Power Unit Parts

Engine Oil

Engine oil has many roles in the modern motorcycle engine, such as lubrication, preventing rust, cooling, cleaning, and sealing the engine. As the engine oil performs these jobs, it will degrade and cause engine problems or breakdowns if not replaced after a certain time or after the motorcycle is ridden a certain distance (listed in the Owner's Manual of each vehicle). Engine oil oxidizes, so it needs to be replaced every 6 months, even if the vehicle hasn't been driven the specified distance.

Oil Filter

The oil filter cleans the engine oil as it circulates through the engine. If the oil filter is not periodically replaced it can get clogged with debris and the engine oil can circulate without passing through the filter, which greatly increases engine wear, shortening the life of the engine. Replaceable oil filter assemblies cannot be cleaned, and needs to be replaced with a new filter at least every other time the engine oil is changed.

Air Filter

The air filter assembly removes contamination from the incoming air before it enters the engine. If unfiltered air enters the engine, contaminants such as dust and dirt particles, can cause severe engine wear resulting in loss of engine performance, engine oil consumption and expensive repairs. The filtration performance of the air filter decreases over time due to the dust, dirt and other debris being "caught" in the filter element restricting the amount of air that can enter the engine. For this reason, the filter needs to be periodically inspected and cleaned, or on some models, the filter element must be replaced.


Water-cooled engines use a mixture of coolant and water to cool the engine. Coolant is not corrosive to metal or rubber, and has a higher boiling point than water. If there isn't enough coolant, there is less of a cooling effect, and there will be a risk of overheating. For this reason, the amount of coolant needs to be checked, along with checking for coolant leaks, during routine inspections. Replace the coolant every 2 years.