Lawn mower blades won't engage: Common Causes & How to Fix
1Lawn Mower PTO Clutch
Most Common Solution
Repair Instructions:
The Power Take Off (PTO) clutch in your lawn mower is a crucial part that allows you to manually disconnect the engine from the blades. When the clutch's solenoid gets power, it triggers the clutch to engage the drive belt, which in turn spins the mower blades. However, if the PTO clutch isn't getting power, or if the solenoid is faulty or the clutch is worn out, the blades won't engage. It's important to note that you can't repair a defective PTO clutch; you'll have to replace it.
How to Replace Lawn Mower PTO Clutch
- Disconnect spark plug wire - Locate the spark plug wire and detach it from the spark plug to prevent accidental starting.
- Remove clutch housing - Take out mounting bolts and detach clutch housing to access the PTO clutch.
- Disconnect wiring - Label and remove any electrical wires connected to the clutch solenoid or actuator.
- Remove clutch - Take out the retaining bolt and washers and slide the PTO clutch off the engine crankshaft.
- Install new clutch - Slide the replacement PTO clutch onto the crankshaft, aligning with keyway.
- Install hardware - Replace the clutch retaining bolt and washers and tighten to the specified torque.
- Reconnect wiring - Reattach the electrical wires to the proper terminals on the clutch solenoid/actuator.
- Replace clutch housing - Reinstall the clutch housing using the original mounting bolts.
- Reconnect spark plug wire - Reattach the spark plug wire once the new clutch is installed.
- Test operation - Start engine and engage the blades a few times to ensure proper clutch function.
2Lawn Mower PTO Switch
Most Common Solution
Repair Instructions:
The Power Take Off (PTO) switch is responsible for supplying power to the PTO clutch in your lawn mower. If this switch isn't working properly, it may fail to power the clutch, preventing it from engaging and stopping the mower blades from spinning. To check whether the switch is the issue, you can use a multimeter to test for electrical continuity. If you find that the PTO switch is indeed faulty, you will need to replace it.
How to Replace Lawn Mower PTO Switch
- Disconnect spark plug wire - Locate the spark plug wire and detach it from the spark plug to prevent accidental starting.
- Remove switch housing - Take off cover to access wiring connections on the old PTO switch.
- Disconnect wires - Label and detach the wire leads from the terminals on the faulty PTO switch.
- Unmount switch - Remove any mounting screws or nuts to detach the old PTO switch.
- Install replacement - Position the new PTO switch in the same spot and orient the terminals properly.
- Remount switch - Reinstall any screws or nuts to secure the replacement PTO switch in place.
- Reconnect wires - Referring to labels, attach the wire leads to the correct terminals on the new switch.
- Replace housing - Reinstall the PTO switch housing cover. Ensure it seals properly.
- Reconnect spark plug wire - Reattach the spark plug wire to test operation of the new switch.
- Verify operation - Engage the PTO switch several times to confirm proper operation.