2. Fuel filter issue: A clogged or dirty fuel filter can restrict fuel flow to the engine. This can cause the engine to run lean and produce inconsistent RPMs. Replace the fuel filter if it is clogged or dirty.
3. Governor issues: The governor of a lawn mower engine is responsible for controlling the engine speed. A faulty or misadjusted governor can cause the engine to speed up or slow down erratically. Inspect the governor mechanism and ensure it's functioning correctly.
4. Spark plug issue: A worn-out or dirty spark plug can cause inconsistent ignition, resulting in erratic engine speed. Check the spark plug and replace if it's worn or fouled. Ensure the spark plug gap is set correctly.
5. Air filter issues: A clogged air filter can restrict airflow to the engine, causing it to run lean and produce inconsistent RPMs. Clean or replace the air filter if it's dirty or clogged.
6. Ignition coil: If the ignition coil is weak or faulty it might cause the engine to operate erratically. You can test the ignition coil by disconnecting the spark plug wire then inserting a spark plug into the end of the wire, next crank the engine over while holding the plug near the metal cylinder or ground. If there's a healthy spark then the coil is likely functional, if there is no spark then the ignition coil needs to be replaced.
Remember to follow safety precautions when working on a lawn mower engine, and refer to the manufacturer's instructions for specific procedures related to your model. If the issue persists, it may be best to consult a professional for further diagnosis and repair.
