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 lawnmower pull cord not catching? The most likely cause of the 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.
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. Let’s just take a minute to understand the basic components involved.
The main components of your lawnmower pull start system include:
- Pull cord
- Pulley recoil spring
- Pulley cover
- 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
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.”
The pull cord is the most likely component to fail. The 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.”
The Pull Cord Handle
Pull cord handle often breaks as the handle can sometimes fly loose during the starting procedure.
The 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.
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 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.
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 you fit a pulley spring, check out “Replacing a pull cord”
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.
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.
The flywheel receiver (fixed to the engine flywheel) seen here has four recesses. The pulley pawls will catch two of these (whichever closest) and turn the engine over.
The 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.
Pull Start Assembly Housing
The pull assembly housing (also known as the blower housing) is, as its name suggests, the outer cover that retains the various pull-start 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.
Pull assembly – Housings will vary in size. Yours may be smaller and less work to remove.
A mower that won’t catch and 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. Check out the pull start troubleshooting video here, which covers all the main faults and the repairs, and if you need parts, check out the great pull starter deals on the Amazon link below.Amazon Lawnmower Pull Starter Parts
Remove plug wire – It’s always best to remove the plug wire before working on your mower, prevents any possibility of it starting.
Remove Honda housing – The housing on a Honda mower is held with 3 fasteners and is typical Honda – very user friendly.
Remove housing – The housing on other mower engines may require a little more work to remove.
Test pull assembly – Test the assemblies by pulling the pull cord – the pawls should shoot outwards from under the pulley cover.
Remove cap – Honda fixed 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. (right)
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.
Remove pawls – 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.
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.
Reassemble, test, and refit your plug wire, and you’re all set, nice work you!
Other Possible Pull Starter 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, they don’t outlive 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.
Flywheel receiver may be plastic or metal – check for damage, wear, or misalignment.
Why can’t I pull the string on my lawnmower? The most common cause of a lawnmower 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