A lawn mower is like a car; it needs annual maintenance.
In addition to oil changes and new air filters, you need to keep a fresh spark plug.
For consistent, easy starting, change your spark plug every 100 hours or every season, whichever comes first.
Replacing your spark plug has several benefits:
Ensures consistent spark
More reliable starting
Improves fuel economy
Step 1: Remove Existing Spark Plug
1. Disconnect the spark plug lead. Then, clean the area around the spark plug to avoid getting debris in the combustion chamber when you remove the plug.
2. Remove the spark plug using a spark plug socket.
3. Clean light deposits from the plug with a wire brush and spray-on plug cleaner. Then, if necessary, use a sturdy knife to scrape off tough deposits. NOTE: Never clean a spark plug with a shot blaster or abrasives.
4. Inspect the spark plug for very stubborn deposits, or for cracked porcelain or electrodes that have been burned away. If any of these conditions exists, replace the spark plug.
Step 2: Replace With New Spark Plug
1. Use a spark plug gauge to measure the gap between the two electrodes (one straight, one curved) at the tip of your spark plug. Many small engines require a .030" gap. Check the specifications for your model.
2. If necessary, use a spark plug gauge to adjust the gap by gently bending the curved electrode. When the gap is correct, the gauge will drag slightly as you pull it through the gap.
3. Re-install the plug, taking care not to over-tighten (15 ft. lbs. MAXIMUM ). Then, attach the spark plug lead.