Many types of lawn and garden equipment are powered by small engines. These engines require periodic maintenance and service to perform properly and to extend the useful life of the engine. Depending on the type of equipment you have, you will find some four-cycle engines and some two-cycle engines as power sources. Small, lightweight equipment such as chainsaws, weed trimmers, leaf blowers and hedge clippers will usually be powered by two-cycle engines. Two-cycle engines will be approximately one-half the size of a same horsepower four-cycle engine. They have no oil crankcase, so the engine can be operated in a variety of positions. For example, chainsaws are operated on their side and even upside down in some cases. There is no problem with engine oil leaking out of the engine when sideways or upside down. The saw will be lightweight and easier to handle with the two-cycle engine. Usually, equipment you would pick up and carry during use will be equipped with two-cycle engines. Equipment that is larger and heavier that you push, pull or ride on will usually have a four-cycle engine. Lawn mowers, garden tillers and garden tractors normally have four-cycle engines.

Knowing the difference between engine types will enable you to perform the proper maintenance on each type of engine. You will need to change the oil in a four-cycle engine periodically while this is not needed for a two-cycle engine. You will need to add two-cycle oil to the gasoline for a two-cycle engine for proper lubrication, but this is not needed with a four-cycle engine.

Four-cycle engines use motor oil which should be drained and replaced every 50 hours or less. Make sure you use the proper viscosity of oil or you can damage the engine. SAE-30 oil is usually best when engines are operated in temperatures above 40 degrees F. For temperatures below 40 degrees, use an SAE 10-30 viscosity. Clean or replace the air filter at least once season or when it appears to be very dirty. Make sure you use clean, fresh gasoline. This is the most common cause of hard engine starting. Gasoline more than 90 days old is stale and will cause hard starting or no starting. Keep the fuel clean. Small amounts of dirt, grass, water or other foreign material in the fuel system will cause problems.

Two-cycle engines use a mixture of oil and gas for fuel. Make sure you mix the proper amount of two-cycle oil with the gasoline for easy engine starting and full power. Never use motor oil mixed with gasoline in two-cycle engines. You will damage the engine and greatly shorten engine life. Clean or replace the air filter at least once each season. Since two-cycle engines use both gas and oil for fuel, you will need to replace the spark plug more often. If the spark plug looks black and greasy, it probably needs replacement. Use clean, fresh gasoline when making the fuel mixture. By adding a fuel stabilizer available at most discount stores, you can keep gasoline fresh up to two years and gas-oil mixes fresh up to one year.

Take care of your small engines and they will last longer and do a better job for you!