How to Tune Up a Lawn Mower – 5 Easy Steps

You need a well-maintained lawn mower to keep your lawn neat. A lawn mower needs a tune-up at least once a year. This helps prevent costly repairs, maximize performance and extend the equipment’s life.

At the start of a mowing season, change the mower engine oil, replace the spark plug and air filters, recharge the battery and sharpen the lawn mower blades. This will give you a smooth start in mowing your lawn.

Lawn mower manufacturers recommend a thorough lawn mower servicing every 50 hours of operation or once per season. However, it can be more often depending on your mowing conditions.

Generally, reduced engine power, more fuel consumption, problem starting up, lawn mower sputtering, stalling, and noises from the engine should necessitate a thorough inspection and servicing.

How to Tune up a Lawn Mower – Steps

Tuning up a lawn mower is best done by a recommended dealer. With little skill, you can as well do it yourself. Ensure to work in a well-ventilated area, turn off the mower, and disconnect the spark plug cable.

1. Change the lawn mower oil

Oil is an important addition to the engine. It lubricates the moving parts to reduce friction and overheating of the engine. Over time, oil gets dirty and worn out and will no longer offer protection to the engine.

Lawnmower manufacturers recommend changing engine oil after 40 to 50 hours of operation. It should be done at least once per season for large engines found in tractors and riding lawnmowers. If you just purchased a new lawn mower, change its oil immediately after 5 hours of runtime.

How much oil your lawn mower takes will depend on your engine size and the make. The large engines will definitely take more oil than the small ones. Refer to your owner’s manual for the exact amount of engine oil your lawn mower take.

Here is how to change the oil:

  • Purchase the right type of oil for your lawn mower as the user manual recommends. You can also get the information from the brand’s website or by contacting them directly.
  • Run your lawn mower for about 10 minutes to warm the oil, then shut off the engine and disconnect the spark plug wire to prevent any possibility of the engine accidentally starting.
  • Drain the oil from the engine. Depending on the model, there are several ways of draining oil from lawn mower engines. It can be done through the dipstick tube, drain plug, or suction pump.
  • Place the lawn mower on the flat ground, screw the drain plug back and fill it with new oil. Use the provided dipstick to check the oil level. It should be close to the maximum line.
  • Replace the oil cap and the dipstick, connect the spark plug wire and start the engine. Spilled oil on the engine will burn out into white smoke.

Tip: In two-stroke engines, a special oil known as 2-cycle or 2T is mixed with fuel in a recommended ratio. In 4 stroke engines, oil and gas are added in separately.

2. Replace the lawn mower air filter

Air filters help trap dust, dirt, and other debris from the air before entering the engine. Air is required in the engine for ignition and combustion of fuel. Air and gasoline are mixed in a given ratio within the carburetor before the mixture is directed into the engine combustion chamber.

You should replace your mower’s air filter during the engine tune. The new dual-element foam filter will ensure clean air gets into the engine. Clean air will boost engine performance, enhance fuel consumption and increase the engine life.

Here is how to replace the air filter:

  • Disconnect the lawn mower spark plug wire to prevent any chance of the engine starting accidentally.
  • Unscrew the air filter cover, usually held in place with a long screw or a nut and a bolt.
  • Remove the current clogged air filter and install a new one of the same type.
  • Screw or bolt the air filter housing, reconnect the spark plug wire and start your lawn mower.

Tip: Regularly clean your mower’s foam filter using a grease-cutting soap to make it effective again. After thoroughly rinsing, dap it with paper towels and spray it with little oil before installing it.

3. Change mower spark plugs

A spark plug is a very important part of the engine ignition and combustion system. It produces a spark that ignites the air-gas mixture in the engine. Over time, the lawn mower spark plug becomes dirty or corroded, impairing its operation.

Here is how to replace the spark plug:

  • Check in the owner’s manual for a recommended type of spark plug for your lawn mower.
  • Locate the spark plug on your lawn mower and disconnect its ignition cable (wire).
  • Use a spark plug socket to remove the current spark plug and install a new one. Be careful not to tighten it too much, as this can damage the delicate parts or break the spark plug.
  • Once done, reconnect the spark plug wire, then start the engine for testing.

Tip: Cleaning spark plugs regularly keeps them effective for longer. Abrasive cleaners like a wire brush and a spark plug cleaner spray are what you need to keep your spark plugs clean.

4. Recharge the battery

This applies to electric cordless or riding lawnmowers whose features rely on battery. When preparing your machine for the mowing season, it’s important to inspect the battery and its charging system. Ensure it is fully charged before starting the engine.

Further, check to ensure that the compartment in which your battery is sitting is clean and dry. This is to minimize the chances of corrosion on the battery terminals. If you are using a corded mower, be sure to check the entire cord for any exposed wire or damage.

Always store your lawn mower battery in a clean, dry place during winter storage. Doing so will help extend the life of the mower battery. With proper care and maintenance, a good battery should last at least 3 years.

5. Sharpen lawn mower blades

As part of routine maintenance, sharpen the lawn mower blades. This makes cutting grass easier and more accurate. Blunt blades are notorious for tearing up grass blades, which won’t be healthy for your lawn.

Final Thought

Tuning up a lawn mower is a very important process that needs to be carried out every season. Winterizing your lawn mower for storage will also give you an easy start in spring when the mowing activities resume.


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