öljynruiskua

Öljynruiskua, meaning "oil injection" in Finnish, refers to a system used in certain two-stroke engines to deliver lubricating oil directly to the engine's crankcase and internal components. This method contrasts with the older practice of pre-mixing oil with the fuel. The oil injection system typically involves a separate oil reservoir, a metering pump, and lines that feed the oil to specific points in the engine, such as the crankcase intake or directly into the carburetor.

The primary advantage of oil injection is its ability to provide a more consistent and precise lubrication ratio. The pump adjusts the oil flow based on engine speed and load, ensuring adequate lubrication under varying operating conditions. This can lead to reduced engine wear, cleaner combustion due to optimized oil-fuel mixture, and less smoke from the exhaust compared to manual pre-mixing. It also eliminates the inconvenience of having to mix oil and fuel before each refueling.

However, oil injection systems add complexity to the engine. They require a dedicated oil tank that needs to be refilled, and the metering pump itself is an additional component that can potentially fail. If the oil pump malfunctions or runs dry, it can lead to severe engine damage due to lack of lubrication. Many modern small two-stroke engines, particularly those found in motorcycles, chainsaws, and outboard motors, utilize oil injection systems for improved performance and longevity.