How Much Oil Should Be Added to a Four-Stroke Lawn Mower?
2 Answers
Due to differences in brand and model of lawn mowers, the method of adding oil may vary. When adding fuel, there is no need to fully pull out the anti-loss plastic string inside the fuel cap; you can add fuel directly as is. Add an appropriate amount of fuel, but do not overfill. For four-stroke engines, oil and gasoline are added separately. Generally, there are no major issues with gasoline, but the oil must be added according to the oil dipstick. The oil level should not be below the minimum mark nor exceed the maximum mark on the dipstick. Excessive Valve Clearance: Delayed opening of the intake and exhaust valves prolongs the intake and exhaust time, reduces the valve lift, alters the normal valve timing, and causes the engine's power to drop due to insufficient intake and incomplete exhaust. Additionally, it increases the impact and accelerates the wear of the valve train components. Insufficient Valve Clearance: After the engine operates, the components expand due to heat, pushing the valves open and causing them not to seal tightly. This results in gas leakage, reduced power, severe carbon buildup or burning on the valve sealing surfaces, and even valve collision with the piston.
I have been using a four-stroke lawn mower for years to maintain my yard, frequently needing to add engine oil, typically between 500 to 700 milliliters. However, the amount varies significantly by model—smaller brands may require as little as 400 ml, while major brands like Honda can go up to 800 ml. The most reliable method is to check the user manual or the oil cap label; never guess. I once overfilled it, causing oil to spray out, smoke, and damage parts. When performing the task, ensure the engine is completely cool, remove the spark plug for safety, and use the dipstick to verify the oil level is between the min and max marks. It's best to use high-grade oil like SAE 30, which is suitable for all seasons. Adding oil at the start of each season, along with cleaning the air filter, can extend the mower's lifespan tenfold. If you've lost the manual, simply search online for your model's specifications. Don’t skimp by buying low-quality oil—it can cause frustrating stuttering during mowing.
