Lawn mower pull cord not catching

Without a pull cord we’re going nowhere, unlike a car we can’t boost it. Hey, I know the feeling when your day doesn’t go to plan, not to worry, you’ve come to the right place.

Why is my lawn mower pull cord not catching? The most likely cause of mower pull cord not catching and turning over the engine, is worn Pawls.

What are Pawls? Pawls are spring loaded arms that catch the flywheel and turn over the engine. 

In this post we’ll look in more detail at what a Pawl is, what it does and more importantly how you can take action today and get it fixed. Strap yourself in!

This post covers pull cord issues pretty well. However if you need video help, check out “Pull cord faults video”. It covers diagnosing pull cord problems and their step by step repair processes.

Mower engine pull cord assembly

Pull assembly pawls

Pull assembly components and what they do

Pull cords work hard and do give their fair share of problems. Having an understanding of how a pull start works will help when repairing. Lets just take a minute to understand the basic components involved.

The main components of your lawn mower pull start system include:

  • Pull cord
  • Handle
  • Pulley
  • Pulley recoil spring
  • Pulley cover
  • Pawls
  • Flywheel pawl receiver
  • Pull assembly housing

The most common pull cord problems listed in order of commonality, include:

  • Pull cord snapped
  • Broken pull cord handle
  • Pull cord recoil spring failure
  • Damaged pull cord pulley
  • Damaged pulley pawls
Mower pull cord

pull cord

The Pull Cord

The pull cord is the most likely component to fail. The pull cord wraps around the pulley and the pulley lives inside the pull assembly housing.

Replacing the pull cord will require removing the pull assembly housing. I wrote a post about it here “Replacing a pull cord”

Mower pull cord handle

handle

The Pull Cord handle

Pull cord handle often breaks as the handle can sometimes fly loose during the starting procedure.

Problem is, the cord may retract back inside the mower. This will require removing the pull start housing to re-tension the spring and fit the new handle.

Mower engine recoil spring and pulley

pulley

When fitting a new pulley, best to opt for the spring and pulley combined.

Springs can be difficult to handle and the combo, for a few extra dollars saves a lot of frustration.

The pulley

The pulley is central to the whole mechanism. Its functions include, guiding, feeding and storing the pull cord, retaining the recoil spring and housing the pawls.

Pulleys are made from plastic and will often crack causing the cord to bind. Replacing the pulley will require removing the pull assembly and it’s better to replace the pulley and recoil spring together.

Mower pull cord recoil spring

spring

pulley recoil spring

The pulley recoil spring is responsible for retracting the cord after pulling.

The spring lives in the center of the pulley and is anchored against a spud on the pull assembly housing.

To replace the spring, (usually replaced with the pulley) the pull assembly housing will need to be removed and also the pulley. If your fitting a pulley spring check out “Replacing a pull cord”

Mower pulley cover

cover

The Pulley cover

The pulley cover is also made from plastic, its functions include fixing the pulley axle in place and guiding the pawls in and out. Pulley covers are made from plastic usually and can simply crack due to wear and tear.

Replacing will require removing the pull assembly housing but not the pulley.

Mower pull assembly pawls

pawls

the pawls

The pawls are also made from plastic but some models use metal. Their function is to fly outwards under centrifugal force caused by the pulling of the pull cord.

When the pawls are flung out, they catch on the flywheel receiver which causes them to couple. The engine now turns over and when the engine starts, the pawls retract.

Mower flywheel receiver

flywheel receiver

The flywheel receiver (fixed to the engine flywheel) seen here, has four recesses.

The pulley pawls will catch two of these (which ever closest) recesses and turn the engine over.

flywheel receiver

Flywheel pawl receiver is a metal cup fixed to the flywheel. When the pulley pawls connect with the receiver, they couple and crank over the engine.

Receiver’s don’t generally cause much trouble.

Mower pull assembly Mower pull assembly

housing

Pull start assembly housing

The pull assembly housing is as its name suggests the outer cover that retains the various components.

The housing is commonly made from plastic and usually doesn’t cause problems. Most repairs will require removing the pull assembly housing. Removing them isn’t difficult.

Some housings will be large and cover the whole engine, while others will be far more user friendly and just be large enough to house the pulley.

Mower pull assembly

Pull assembly

Housings will vary in size, yours may be smaller and less work to remove.

Replacing pawls

A mower that won’t catch an turn the engine most likely has a faulty pawl issue. The pawls are made from plastic as you know, simply wear out. There are other possible reasons that the engine won’t catch and turn and we’ll look at them below.

Basic tools are needed and the whole job shouldn’t take more than thirty minutes.

Removing lawn mower plug wire

Remove plug wire

It's always best to remove the plug wire before working on your mower, prevents any possibility of it starting.
Honda lawn mower Lawn mower pull assembly removed

Remove housing

The housing on a Honda mower is held with 3 fasteners and is typical Honda - very user friendly.
Lawn mower Lawn mower pull assembly

Remove housing

The housing on other mower engines may require a little more work to remove.
Honda mower pull assembly Mower pull assembly test

Test pull assembly

Test the assemblies by pulling the pull cord - the pawls should shoot outwards from under the pulley cover.
Mower pull cover Mower pull assembly repair

remove cap

Honda fix their cap using a Torx head screw, it's important to know that it is a left hand thread. Meaning to remove the screw turn the Torx head clockwise.

Other types may use a clip, the clip just slides off, but I place a rag over the clip when removing as these guy's can fly and you could spend a whole afternoon searching and still never find it.

Mower pull assembly pawls Mower pawls

remove pawls

Mower pawls Mower pull assembly pulley cap

Check

Your pulley pawls may be worn, damaged or just dry. Remove them to examine.

The pawls should fit snugly in the pulley, if they're loose, they're worn.

On the top side of the pawls, you should see a spud, it seats in the track of the cap. If the spud is missing or worn go ahead and replace the pawls.

If however the pawls are just dry, put some silicone grease on them, reassemble and test.

The pulley cap must also be checked for wear and damage. A damaged cap will prevent the pawls from working.

Lubing the pull assembly pawls Tractor mower seal out

fitting pawls

Add a small amount of lube on the new pawls and cap, it will help them work smoothly and they'll last longer.
Mower old oil seal

Reassemble & test

Good job, after reassembly, refit your plug wire and your all set.

other possible issues

So what if my pawls and cap look good, what else could cause the problem?

Other possibilities include:

  • Damaged pulley
  • Damaged receiver

The pulleys are made from plastic so don’t out live the engine. A cracked or worn pulley will cause the pawls to bind and stick. Replacing a pulley is a little more work, but is a job you can take care of yourself. I’ve written a post about it here “Pull cord repair”

A damaged receiver isn’t very common but it can happen. Most are made from metal and are durable but others are made from plastic and you know what happens to plastic.

So if your pawls looked fine focus your attention on the pulley and receiver.

Mower pull assembly pulley

Check for wear and cracks

Mower flywheel pulley pawl receiver Mower flywheel pulley pawl receiver

check for damage

Flywheel receiver may be plastic or metal - check for damage, wear or misalignment.

Related Questions

Why can’t I pull the string on my lawn mower? The most common cause of a lawn mower string not pulling, is worn pull assembly pawls. However, other possible causes include:

  • Sticking flywheel brake
  • Pull assembly failure
  • Blade jammed
  • Crankshaft bent
  • Engine sized
Auto Technician and Writer at | Website

John Cunningham is an Automotive Technician and writer on Lawnmowerfixed.com. I've been a mechanic for over twenty years, I use my knowledge and experience to write "How to" articles that help fellow gear-heads with all aspects of mechanical repairs, from lawn mowers to classic cars.