Learn which plants thrive in your Hardiness Zone with our new interactive map!

How to Put a Tach Meter on a Lawnmower

By Justin Wash ; Updated September 21, 2017

Installing a tachometer on your lawn mower is especially useful in finding the limits to which your mower will cut without bogging down or dying. By watching the tachometer, you may determine more precisely the speed of the engine on your mower in order to keep it running, saving you time trying to restart it after it dies. Monitor your lawn mower’s performance by installing a tachometer on your own.

Remove your tachometer from the packaging. Use a socket wrench to remove the engine cover from your lawn mower. Refer to your owner’s manual for directions specific to your mower model

Locate the spark plug and spark plug wire beneath the engine cover. This is where the tachometer’s reader wire will be installed.

Wrap the tachometer’s reader wire around the spark plug wire, near where it attaches to the spark plug boot. Use one zip tie near the boot, and one at the end of the coil to secure the reader wire to the spark plug wire.

Remove a bolt from the engine block. Set the ground wire of the tachometer underneath the bolt head and tighten the bolt down on top of it. This will ground the tachometer.

Follow the lawn mower’s handlebar with the tachometer’s cables, securing them with evenly spaced zip ties to keep them from getting caught or tangled when the mower is in use. Secure the tachometer to the handlebar where it will be easily visible while mowing.

Reinstall the engine cover of your lawn mower using a socket wrench. Start the lawn mower and look for a reading on the tachometer. By intentionally overworking the mower, you can watch the tachometer and learn its limits.


Things You Will Need

  • Gas-powered lawn mower
  • Basic wrench set
  • Zip ties
  • Tachometer

About the Author


Born and raised in St. Louis, Mo., Justin Wash began his professional writing career in 2004 with an online freelance copywriting business. Over the years, he has written for a myriad of clients including China-Vasion and The Executives Closet.