What kind of oil does a grass trimmer use?
3 Answers
Green grass trimmers are equipped with two-stroke gasoline engines, and the ratio of gasoline to engine oil can be either 25:1 or 30:1. A two-stroke gasoline engine has three holes on the cylinder block: the intake hole, exhaust hole, and scavenging hole, which are closed by the piston at specific times. Its working cycle consists of two strokes. Description: First stroke: The piston moves upward from the bottom dead center, and after the three holes are simultaneously closed, the mixed gas entering the cylinder is compressed; when the intake hole is exposed, the combustible mixed gas flows into the crankshaft case. Second stroke: When the piston is compressed near the top dead center, the spark plug ignites the combustible mixed gas, and the expanding gas pushes the piston downward to perform work. At this time, the intake hole is closed, and the combustible mixed gas sealed in the crankshaft case is compressed; when the piston approaches the bottom dead center, the exhaust hole opens, and the exhaust gas rushes out; then the scavenging hole opens, and the pre-compressed combustible mixed gas rushes into the cylinder, expelling the exhaust gas to complete the scavenging process.
As a seasoned user with over a decade of lawn mower experience, let me share some practical insights: Lawn mowers primarily rely on two components—gasoline and engine oil. For fuel, regular unleaded gasoline works fine, like the 87-octane type sold at gas stations. Avoid diesel as it can severely damage the engine. As for engine oil, it depends on the engine type. For common four-stroke mowers, SAE 30 or 10W-30 oil is ideal. Regular changes, approximately every 25 hours of use, can extend the machine's lifespan. I recall once using oil with the wrong viscosity—the machine buzzed loudly until I cleaned the engine to fix it. Always remember to turn off the engine before refueling—safety first, as spilled fuel can ignite dangerously. Also, avoid storing gasoline in the garage for too long as it can evaporate and degrade. Before winter, thoroughly clean the fuel tank to prevent residue buildup and avoid startup issues in spring.
When I first started maintaining my lawn, I was completely clueless about what oil to use for the lawn mower. But it turned out to be quite simple: the fuel is just regular gasoline—no need for expensive stuff, it’s a waste of money. As for the engine oil, checking the machine’s manual is the most reliable approach. My old mower is a two-stroke model, so I had to buy special two-stroke oil and mix it with gasoline at a 50:1 ratio. Otherwise, it would emit black smoke when starting, which annoyed the neighbors. Beginners shouldn’t panic—there are online tutorials on oil mixing, or you can just buy pre-mixed fuel. I also learned to check the oil level weekly, keep it clean, and avoid dust clogging the filter. Once, I operated it on a rainy day, and the slippery ground almost caused an accident, so it’s best to postpone maintenance in bad weather. I recommend trying small tasks a few times first and then saving money by changing the oil yourself once you’re comfortable.
