How to Tune Up a Lawn Mower


Proper maintenance is important to any equipment. Without proper care, the equipment will not last. Owners of lawn mowers, be they riding mowers or push mowers, should regularly perform several key maintenance tasks. Among these are washing the unit, checking tire inflation and doing routine tune-ups. All of these things can help extend the life of the mower, but none is more important than a proper tune-up.

Step 1

Locate the motor for the mower. This is easy with a traditional push mower. Most riding mowers have the engine located under the front hood. Some mowers will have the engine under the operators seat.

Step 2

Locate the spark plug(s) on the engine. The best way to locate these is to follow the plug wires to the end of the engine cylinders. In most mowers, the spark plugs will be at the front corners of the mower. For some mowers, the spark plugs will be on top of the engine.

Step 3

Remove the plug wires from the plugs. This is done by grasping the wire boot and wiggling the boot while pulling until the boot comes off the plug.

Step 4

Remove the plug(s) with the spark plug socket and ratchet. Spark plug sockets generally come in two sizes; most mowers will use the larger of the two sizes. Make sure the ratchet is set to loosen before attempting to remove the plugs; over-tightening will damage the engine.

Step 5

Place a small spot of anti-seize compound on the threads of the new plug(s).

Step 6

Install the new plugs. Make sure the plugs do not cross-thread. Do not over-tighten the plugs, as this will cause engine damage.

Step 7

Press the plug wire(s) back onto the new plugs. Make sure they "click" onto the top of the new plugs.

Step 8

Remove the old air filter. Most mowers will not require any tools to remove the air filter.

Step 9

Install the new air filter. Some mowers have a two-part air filter; in this case both parts of the air filter should be replaced.

Step 10

Add the fuel system cleaner to the a full tank of fuel. If a fuel system cleaner for a car is used, only add half the bottle to the tank.

Tips and Warnings

  • Make sure to use the anti-seize compound on the new plugs, as this will make it easier to remove the plugs later. Do not get the anti-seize compound on anything but the threads of the new plugs.

Things You'll Need

  • Ratchet
  • Spark plug socket--correct size for the plugs in the motor
  • Anti-seize compound
  • New plug(s)
  • Air filter
  • Fuel system cleaner


  • Clarence White, Toro Certified Mechanic; Berlin, Md.
  • Mower Tune-Up
Keywords: mower tune up, tune up, mower maintenance