The recommended spark plug gap for a Briggs and Stratton 12.5 HP lawn mower that is 10 years old may vary depending on the specific model and engine type. However, in general, the spark plug gap should be set according to the manufacturer's specifications found in the owner's manual or service guide for your particular mower.
Here's a general guideline for setting the spark plug gap on a Briggs and Stratton 12.5 HP lawn mower:
1. Locate the Spark Plug:
- Turn off the engine and allow it to cool down completely.
- Disconnect the spark plug wire from the spark plug to prevent accidental ignition.
- Use a spark plug wrench to remove the spark plug from the cylinder head.
2. Check the Spark Plug Gap:
- Hold the spark plug with the electrode facing upwards.
- Use a feeler gauge (a thin, flat metal tool with incremental measurements) to measure the gap between the center electrode and the side electrode.
- The gap should be within the range specified by Briggs and Stratton for your specific engine model. Common gap settings can range between 0.020" to 0.030".
3. Adjust the Spark Plug Gap if Necessary:
- If the spark plug gap is too wide or too narrow, use a spark plug gap tool or a small needle-nose pliers to gently bend the side electrode until the desired gap is achieved.
- Be careful not to damage the spark plug or its electrodes.
4. Reinstall the Spark Plug:
- Screw the spark plug back into the cylinder head by hand until snug.
- Use the spark plug wrench to tighten the spark plug. Do not overtighten.
- Reattach the spark plug wire to the spark plug.
Note: It's essential to follow the manufacturer's recommended spark plug gap specifications for your Briggs and Stratton 12.5 HP lawn mower to ensure optimal performance, fuel efficiency, and longevity of the engine. If you're unsure about the correct gap or have difficulty adjusting it, consult the owner's manual or seek assistance from a qualified small engine repair professional.
