Why is it hard to pull cord on lawn mower?

Quick Answers

There are a few common reasons why it can be difficult to pull the starter cord on a lawn mower:

• The engine is seized up due to lack of oil, old gas, or corrosion
• The spark plug is fouled or faulty
• The air filter is clogged
• The throttle control is not in the correct starting position
• The blade is jammed with debris
• The recoil spring is worn out

If the mower engine turns over but won’t start, the most likely culprits are issues with the fuel, air intake, or spark plug. However, if the engine won’t turn over at all when pulling the cord, this indicates a seized engine or jammed blade. Regular maintenance like changing the oil, replacing air filters, and cleaning under the mower deck can help prevent many starting issues.

What Makes Starting a Mower Difficult?

When you tug on the starter cord to start your lawn mower, it engages the recoil mechanism which spins the engine flywheel. This allows the spark plug to operate and ignite the fuel in the engine, starting the mower. Here are some of the most common reasons the starter cord can become stubborn or impossible to pull:

Engine Seizure

Over time, residue can build up in the engine from old gas, lack of oil, and corrosion. This sticky buildup prevents the engine flywheel from turning over when the cord is pulled. An engine seized from oil starvation or corrosion usually requires a rebuild or replacement.

Fouled Spark Plug

The spark plug is responsible for igniting the fuel in the engine. If the spark plug becomes coated with oil, fuel residue, or carbon buildup, it can fail to spark properly. This prevents starting until the plug is replaced or cleaned.

Clogged Air Filter

A blocked air filter starves the engine of adequate airflow, making starting difficult or impossible. Cleaning or replacing the filter allows air to flow freely again.

Incorrect Throttle Position

Most mowers require the throttle to be in the choke position for cold starting. If improperly positioned, fuel may not reach the engine properly. Adjusting the throttle lever to the correct starting setting can fix hard starting issues.

Debris Jamming the Blade

Overgrown grass, sticks, rocks, and other debris can become lodged under the mower deck and around the blades. This puts extra load on the engine when pulling the starter cord. Inspecting and clearing any collected debris can help the engine turn over easier.

Worn Out Recoil Spring

The recoil spring provides the force needed to spin the flywheel as the starter cord is pulled. After years of use, this spring can become stretched out or fatigued. Replacing a worn recoil spring is crucial to ensure easy starting.

How to Diagnose the Problem

Pinpointing why your mower won’t start with the pull cord involves checking several areas on your engine. Here is a step-by-step diagnostic process:

1. Check the oil level – Low oil can cause seizure.
2. Inspect the spark plug – Replace if fouled or cracked.
3. Clean or replace the air filter – Clogged filters affect starting.
4. Make sure fuel is fresh – Old gas can gum up the system.
5. Check for debris under and around deck.
6. Try turning the blade manually – It should spin freely.
7. Adjust the throttle to starting position.
8. Test the recoil spring – Replace if loose.
9. Attempt starting again.

If the engine still won’t turn over, you likely have internal seizure or damage. This requires disassembling the engine to inspect further or taking it to a repair shop.

Step-by-Step Instructions for Starting

Follow these instructions when attempting to start your lawn mower to ensure the starter cord pulls smoothly:

1. Check the fuel and oil levels.
2. Adjust the throttle lever to the choke position.
3. Prime the engine if equipped with a primer bulb.
4. Stand behind the mower and grasp the handle.
5. Pull the starter cord quickly with a full arm stroke.
6. Repeat pulling the cord up to 3 times.
7. Push the choke to the run position once the mower starts.

If the engine does not start, wait a few minutes before trying again. This allows fuel to reach the engine. Avoid pulling the cord repeatedly with the choke on, as this can flood the engine. If the cord remains difficult to pull after several attempts, diagnose the underlying issue.

Maintenance to Prevent Starting Problems

Regular mower maintenance goes a long way towards preventing problems with pulling the starter cord. Here are some tips:

• Change the engine oil yearly.
• Replace the spark plug every 100 hours of mowing.
• Clean or replace the air filter periodically.
• Drain old gasoline from the fuel tank before storage.
• Keep the underside of the mower deck clear of clippings.
• Lubricate throttle and choke control cables.
• Check for loose or damaged recoil components.

Preventative maintenance ensures that engine components stay clean and lubricated. It also avoids deterioration from old fuel, oil, and filth that can lead to hard starting issues down the road.

When to Seek Repair Service

While some starter cord problems can be resolved with routine care, others require professional service or repair:

• The engine shows signs of internal damage or oil leakage.
• Removing debris or air filter cleaning doesn’t help.
• The spark plug remains fouled after replacement.
• Cord pulling force feels excessively high.
• You hear grinding noises from the engine.
• The recoil spring and components are severely worn or damaged.

Seeking professional small engine service can diagnose underlying issues like valve problems, low compression, or mechanical wear that prevent starting. Repairs like engine overhauls, valve jobs, and piston ring replacement may be needed in severe cases.

Starter Cord Safety Tips

Pay attention to these safety precautions when pulling the starter cord to avoid injury:

• Keep your hands and feet away from the mower blade at all times.
• Make sure the spark plug wire is disconnected before performing maintenance.
• Wear heavy gloves to protect your hands from the cord.
• Stand with secure footing while pulling the cord.
• Keep children and pets well away from the mowing area.
• Apply even pressure when pulling – don’t yank the cord.
• Wind the cord slowly back into the recoil assembly after starting.

Rope burns, hand injuries, and foot lacerations can result from mishandling the starter cord. Always put safety first by disconnecting the spark plug and wearing protective gloves.

Conclusion

Difficulty pulling the starter cord on your lawn mower indicates an underlying issue that requires diagnosis and repair. Common culprits include engine seizure, spark plug fouling, air filter blockages, debris jams, and recoil spring wear. Regular maintenance can prevent many starting problems, but serious engine damage may require professional service. Exercise caution when pulling the cord by disconnecting the spark plug and wearing heavy gloves to ensure safety. With proper troubleshooting and care, your mower’s starter cord should operate smoothly for years to come.