Dealing with a lawn mower that won’t start can be frustrating, especially if you’re unsure whether the issue is the starter. I’ve been through the same situation and learned how to troubleshoot and identify signs of a bad starter. Fortunately, there are several ways to tell if your lawn mower’s starter is the problem.
Here’s a step-by-step guide to help you determine if your lawn mower starter is bad.
1. No Response When Turning the Key or Pulling the Cord
One of the clearest signs of a bad starter is when nothing happens when you attempt to start the lawn mower. If the engine doesn’t crank, or there’s no sound at all, your starter could be malfunctioning. Here’s how to check:
- Electric Start: If your mower has an electric start and there’s no clicking or engine noise when you turn the key, the starter solenoid or starter motor could be bad.
- Pull-Start: If your mower is manual, and the pull cord doesn’t engage the engine or spins loosely without resistance, the recoil starter mechanism might be broken.
2. Starter Makes Clicking Noise
A rapid clicking noise when you try to start the mower typically points to a problem with the starter solenoid or starter motor. If you hear clicking, the solenoid might be functioning, but the starter isn’t getting enough power to engage the engine.
- Weak Battery: Sometimes a clicking sound can indicate a weak battery rather than a bad starter. Test the battery first to ensure it’s fully charged before checking the starter.
3. Grinding Noise from the Starter
If you hear a grinding noise when you try to start the mower, it’s often a sign that the starter gear or flywheel teeth are worn or damaged. The grinding noise happens when the starter gear isn’t engaging properly with the flywheel, causing the gears to slip.
- Worn Teeth: Inspect the starter gear and flywheel for worn or broken teeth, as this could prevent the starter from properly engaging the engine.
4. Smoke or Burning Smell
If you notice smoke or a burning smell coming from the engine or starter area, it could be a sign that the starter is overheating or the wiring is damaged. This usually indicates an electrical issue, such as a short circuit in the starter motor, solenoid, or wires.
- Worn Starter Motor: Over time, the starter motor may wear out, and if it overheats, it can emit smoke. Stop trying to start the mower and disconnect the battery to avoid further damage.
5. Starter Spins But Doesn’t Engage the Engine
In some cases, the starter motor may spin, but the engine won’t crank. This usually points to a problem with the starter gear, which isn’t engaging with the engine’s flywheel.
- Damaged Bendix Gear: If the Bendix gear (the small gear that extends to meet the flywheel) is worn or broken, it won’t be able to catch the flywheel, meaning the engine won’t start even though the starter motor is running.
6. Test the Starter Solenoid
If you suspect the starter solenoid (the relay that connects the starter to the battery) is the issue, you can perform a simple test:
- Check the Connections: Ensure the wires leading to the solenoid are tight and free of corrosion.
- Jump the Solenoid: With a screwdriver, touch the metal contacts on the solenoid to bypass it. If the engine cranks when bypassing the solenoid, the solenoid is bad and needs replacing.
7. Check the Battery and Cables
Sometimes a starter issue is related to the battery or cables. Before replacing the starter, check the following:
- Battery: Make sure the battery is fully charged and providing enough power to the starter.
- Battery Cables: Inspect the battery cables for corrosion or loose connections. Clean any corrosion off the terminals and ensure the cables are tightly connected.
8. Perform a Voltage Test on the Starter
If the above steps don’t point to a specific issue, you can use a multimeter to test whether the starter is receiving enough voltage:
- Connect the Multimeter: Set the multimeter to measure voltage and connect it to the positive and negative terminals on the starter.
- Check Voltage: When you try to start the mower, the voltage should remain steady and not drop significantly. If the voltage is low or drops, it could indicate a weak battery or a bad starter.
Conclusion
If your lawn mower exhibits any of these symptoms—no response, clicking, grinding, smoke, or a starter that spins but doesn’t engage—it’s likely that your starter or starter solenoid is bad. Always start by checking the battery and connections, and then move on to testing the starter and solenoid.
Once you’ve identified the problem, you can either replace the faulty part or take the mower to a professional for repair. By diagnosing the issue early, you can save time and avoid further damage to your mower!