The lubricating and cooling action of oil is essential for all engines. Failure to maintain the proper level of oil, and provide your engine the correct oil mix, can quickly overheat and ultimately ruin your engine, leading to much more consequential and costly repairs. Because 2-stroke engines require both oil and gasoline mixed within the fuel tank, always refer to the owner's manual for the proper mixing ratio of gas to oil. Always check if your oil level is sufficient in 4-stroke engines.