How to Check a Spark Plug on a Lawn Mower
If your lawn mower isn’t starting or is running rough, a faulty spark plug could be the culprit. Checking and replacing the spark plug is a relatively simple task that can help keep your lawn mower in good working condition. In this article, we’ll guide you through the process of how to check a spark plug on a lawn mower.
Materials Needed
Before you begin, gather the following materials:
– Spark plug socket and ratchet
– Spark plug gapper (optional)
– Replacement spark plug
– Insulated gloves
– rag or towel
Step 1: Safety First
Safety should always be your top priority. Before you start, make sure the lawn mower is turned off and disconnected from the power source. It’s also a good idea to wear insulated gloves to protect yourself from any accidental electrical shocks.
Step 2: Locate the Spark Plug
Most lawn mowers have the spark plug located on the engine. Look for a metal cylinder with a threaded end. This is the spark plug. It may be covered by a rubber or plastic cap.
Step 3: Remove the Spark Plug
Using the spark plug socket and ratchet, carefully remove the spark plug from the engine. Be sure to hold the socket steady to avoid stripping the threads.
Step 4: Inspect the Spark Plug
Once the spark plug is removed, inspect it for any signs of damage or wear. Look for the following:
– Black or gray soot on the electrode: This indicates a rich fuel mixture and may require a carburetor adjustment.
– Rust or corrosion: A spark plug with rust or corrosion may not produce a strong spark and should be replaced.
– Broken electrode or porcelain: If the electrode is broken or the porcelain is cracked, the spark plug needs to be replaced.
Step 5: Gap the Spark Plug (Optional)
If you’re not sure whether the spark plug is gapped correctly, you can use a spark plug gapper to check. The recommended gap for most lawn mower spark plugs is between 0.020 and 0.030 inches. Adjust the gap if necessary.
Step 6: Clean the Spark Plug
Wipe the spark plug with a rag or towel to remove any dirt or debris. This will help ensure a clean spark and prevent engine issues.
Step 7: Install the New Spark Plug
If the spark plug is damaged or worn, replace it with a new one. Make sure to tighten it securely, but don’t overtighten it. Over-tightening can damage the threads in the engine.
Step 8: Reassemble and Test
Reassemble the spark plug cap and reconnect the spark plug wire. Start the lawn mower and check for proper operation. If the engine runs smoothly, you’ve successfully checked and replaced the spark plug.
By following these steps, you can ensure that your lawn mower’s spark plug is in good condition and your engine runs efficiently. Regularly checking and maintaining your spark plug can help prevent costly repairs and extend the life of your lawn mower.
