How to Replace a Lawnmower Sparkplug

Spark plugs wear out. It is wise to replace the spark plug every season as part of your lawn mower maintenance. Here is how to do it.

Things You'll Need

• Lawn mower owner's manual
• Socket wrench
• Spark plug socket
• New spark plug
• Spark plug gap tool or feeler gauge

Instructions

1. Locate the spark plug on your lawn mower. If you don't know where the spark plug is, then you need to have a professional change the plug for you.

2. 

   For safety's sake, remove the spark plug wire and keep it away from the spark plug. This is a very important step. You must remove the spark plug wire first.

3. Use a socket wrench and the proper spark plug socket to remove the old plug. Usually, you'll have to turn the spark plug to the left to loosen it. If you have your owner's manual, check to see what type of socket wrench you'll need to remove the plug.

4. Gap the new plug. Most spark plugs come pre-gapped, but you might have to refer to your owner's manual to see if you have to set the gap on the new spark plug. Set the new gap with a spark plug gap tool or feeler gauge.

5. Screw in the new spark plug. Make sure you do not over tighten the new plug or you will break the ceramic on the new spark plug. Hand tighten the new plug.

6. Reconnect the spark plug wire. Make sure the wire is clean and that it fits on the spark plug head tightly.

7. That's it. The mower should start up and run fine. If not, check the owner's manual for additional troubleshooting and make sure you have gas in the mower.

Tips & Warnings

• Remember to disconnect the spark plug wire before beginning.

• Keep the wire away from the spark plug while working.

• Do not over tighten the new plug.