How to Tune Up a Lawn Mower – 5 Easy Steps

You need a well maintained lawn mower to keep your lawn neat. A lawn tractor, push or riding lawn mower needs a tune-up at least once a year. This help in preventing costly repairs, maximize performance and also extend the life of your equipment. Here is how to tune up a lawn mower.

Lawn mower tune up is a simple task that involves inspecting and replacing components of the engine that are essential for ignition and operation. They include engine oil, air filters, spark plugs and sometimes battery. Spring is the best time to tune up your lawn mower when you are about to start mowing.

Although the tune up interval for a lawn mower is about every 50 hours of operation or once per season, you may have to do it based on conditions under which your machine works. High ambient temperatures, dusty conditions or tall grass will necessitate more or frequent tune ups.

Reduced engine power, more fuel consumption, problem starting up, stalling and funny noise from the engine are some of the signs that your lawn mower needs servicing or tune-up.

How to Tune up a Lawn Mower – Steps

While you may take your mower to a repair shop for tuning up, getting your hands dirty a little can save you some costs and earn you some experience. Before you start, your safety is very important. Work in a well-ventilated area, with a turned off the mower engine and disconnected spark plug cable.

1. Change the lawn mower oil

Oil is an important part of an engine. It lubricates the moving parts which reduce friction and overheating of the engine. Overtime, oil gets dirty and worn out and will no longer offer the much needed protection to the engine. This is why you need to change the oil regularly or as recommended in the owner’s manual.

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

How much oil your lawn mower take will depend on the size of your mower’s engine as well as the brand. Large engine will definitely take more oil as compared to the small ones. Make reference to your owner’s manual for the exact amount of engine oil your lawn mower take. Below is how to change oil:

  • Purchase the right type of oil for your lawn mower as recommended in the user manual. You can as well get the information from the brand website or by contacting them directly.
  • Run your lawn mower for about 10 minutes to warm the oil, shut off the engine and disconnect spark plug wire to prevent any possibility of the engine accidentally starting.
  • Drain the oil from the engine. There are several ways of draining oil from lawn mower engine depending on the model. It can be done through the dipstick tube, drain plug or by use of a 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 then connect back 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 separate tanks.

2. Replace lawn mower air filter

Air filters help in trapping dust, dirt and other debris from air before it enters into the engine. Air is required in the engine for ignition and combustion of fuel. Air and gasoline are mixed in a given ration 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 that clean air is getting into the engine. Clean air will boost engine performance, enhance fuel consumption and increase the engine life. Replace the lawn mower air filter as follows:

  • Disconnect the lawn mower spark plug wire to prevent any chance of 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 back.

3. Change mower spark plugs

A spark plug is a very important part of the engine ignition system. It produce a spark that ignites the air-gas mixture in the engine. Overtime, lawn mower spark plug becomes dirty or corroded and this can impair how they operate. During tune up, spark plugs should be replaced as follows:

  • 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 cleaner like a wire brush and a spark plug cleaner spray are what is needed to keep your spark plugs clean.

4. Recharge the battery

This applies for electric cordless or riding lawn mowers whose features rely on battery. When preparing your machine for the mowing season, it’s important to visually 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 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 damages.

Always store your lawn mower battery and cords in a clean dry place during winter or long storage. Doing so will help extend the life of the mower battery. With proper care and maintenance a good battery should last you at least 5 years.

Final Thought

Tuning up a lawn mower is very important process that needs to be carried out every season. Other additional lawn maintenance to be done include sharpening lawn mower blades at the start of mowing season, clean the mower deck after cutting grass to avoid corrosion and growth of mold on the nearby parts.

When storing for longer, stabilize your mower’s fuel. Fuel usually go bad after 30 days but a stabilizer makes it to last more than 24 months. With bad oil in its tank, a lawn mower will not start or stay running. This can give you hard moments when you have eagerly been waiting to trim your lawn.


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