Briggs And Stratton Starter Gear Keeps Breaking? (Do This!)

Ian Haynes
by Ian Haynes

The Briggs and Stratton lawnmower is perfect for cutting and leveling the grass in your backyard or lawn. But, like other electric machines, it’s vulnerable to wear and tear. It’s only normal for a starter to go bad or keep breaking after prolonged usage.

The trouble is that it can be hard to figure out what causes the starter gear to break, especially if it’s the fifth or sixth time. But the most common causes can be loose mountings, worn pinion gear, and worn or missing teeth flywheels.

Also, here’s a quick guide on how to deal with a bad starter. If you want to know more about how starter works, what causes starter the gear to go bad, and how to replace one, read on!

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How Does The Starter Motor Works?

Before finding out what the problem is that keeps breaking your starter gear, you must know how the Briggs and Stratton starter motor works.

The starter motor is a small cylindrical device mostly located on the engine’s lower side where blocks join the transmission. Once you push the ignition key, the battery makes the current, which starts the solenoid – the controlling device.

The starter motor includes a pinion gear, which is attached to a rod. The critical thing to notice here is that this gear is beyond the reach of the mower’s flywheel gear side. Once the solenoid is activated, the lever pushes out the rod and joins the pinion gear and flywheel gear.

The starter spins over the engine to perform the running chain of sequences such as crankshaft rotations, pistons movements, the release of fuel/air mixture to cylinders, etc.

When the engine starts, it means the starter motor has done the job. Also, remember when you take out the key, it gets separated instantly from the flywheel to its original safe location where the starter cools and gets ready for the coming round when called upon.

By now, you should have a fair idea of how the lawn mowers starter motor operates. Now, let’s dive straight into the potential causes for the breakdown of your starter gear.

Why Does Your Starter Gear Break?

You see the grass getting bigger in your lawn or backyard and decide to mow it down. However, when you, the mower keeps stops at different intervals, and it sounds a bit off too

A quick inspection tells you that your starter gear has broken. How? Whether this is the first time you’ve faced a broken or cracked starter gear or the fourth, here are a few of the possible reasons behind this issue:

Loose Mountings

One potential cause of it can be loose bearings. You can hear grinding-like noise when the starter has a loose mounting. It occurs due to standard wear bolts that support the motor experience.

When you’ve got a loose bolt, the starter will not properly engage with the flywheel and cause grinding noise – it happens when pinion gear and flywheel’s ring gear clashes against each other, hence facing breakage. To avoid this situation, you need to tighten each loose bolt. With that, try connecting other wires as well.

Worn Pinion Gear

Another potential cause is wear and tear of the pinion gear. It may have either worn out or face missing teeth that results in constant grinding noise when you push it. As a result, it can crack your starter’s gear and stops the mower from cranking.

Plus, you should also make sure the pinion gears move only in one direction. If this is not the case, try replacing them.

Check The Flywheel

Another likely reason for the starter gear’s breaking is ‘worn flywheel.’ The flywheel is placed in the middle of the transmission and engine. As I already mentioned above, the flywheel is engaged by the pinion gears so that your lawnmower starts.

When flywheel faces wear and tear or missing teeth, just like pinion gear, it causes noise as both parts grind against one another.

These were a few straight reasons that can be the cause of your starter gear breaking. While it’s essential to know about what causes gear breakage, it’s equally important to know about other starter gear issues and a quick way to repair them.

Some Other Common Problems With Starters

Nothing can be more frustrating than when you mow your grass and the mower stops engaging. Here’re a bunch of other common issues that you may face with your starter gear.

Scenario 1

In case the starter gear engages the engine too slowly, chances are you’ve got an issue with the following:

  • Extra load that affects performance, i.e. wrong hydraulic oil
  • Discharged battery, defective battery circuit, small and corroded battery terminals, wrong battery size, etc.
  • Incorrect engine oil viscosity. Use the instruction manual to which lubricants fit accurate to your mower and read this guide to know how much oil is enough
  • Brush wear
  • Wear and tear on starter commutator, weaker magnets, etc.

Scenario 2

In case the starter spins and doesn’t start your lawn mower’s engine, chances are you’re having trouble with the following:

  • Similar to scenario one, the battery can be dead or damaged. See what causes this issue through a thorough inspection of your charging and battery system
  • Wrong spinning because of reversed starter motor polarity. It’s important to note here that motors spin against the clock if seen over a pinion gear. If your lawnmower runs clockwise, make sure to reconnect its battery
  • Slipping clutch. To solve this problem, remove the clutch first. Then, wipe its base as well as bearings and reassemble

How To Replace The Starter Gear From Briggs And Stratton Mower Engine

When the starter gear doesn’t spin out the pulley, it needs replacing. However, you don’t have to rush to an expert technician to fix this problem. Do it yourself, that too at a minimal cost.

Here’s a step by step guide on how to replace starter gear:

  • First, park your Briggs and Stratton mower on a solid, flat surface like a sidewalk or driveway. Then, turn it off and take out its ignition key. Also, don’t forget to use your mower’s parking brakes. Now, unlock the hood so that it cools down
  • Take out the spark plug boot from the engine (if the model you’ve includes two boots, remove both). Turn the lawnmower wing nut against the clockwise and take it out. Now, take out its battery cable – remove the black battery’s cable first and then the red one
  • Use the plier to grab the starter’s lower nut, holding the cable of the red battery. Carefully, turn the bottom nut in the opposite direction to loosens, and you can take it out quickly. Now, remove the cables from the red battery off your starter
  • Remove solenoid wire – a tiny wire connecting the starter’s top – from the starter motor. Use your adjustable wrench to take out the bolts, which are securing the dipstick tube. Very cautiously, spin the tube far from your starter
  • Grab your adjustable wrench and take out the two bolts placed on the top of the starter that joins it with the engine. Put one hand under its bottom and take out the starter gear
  • Replace with the new starter going thru these steps in reverse

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Related Questions

Is There Any Standard Space Between Flywheel And Ignition Coil?

Yes, there’s an accurate distance set between the two. To get precise gap knowledge, go through the lawn mower’s instruction manual. However, one of the most common space ranges is .006 to .010.

How Can I Fix My Briggs And Stratton Mower That Cranks And Die?

Check whether its gas cap vent is blocked, and if that is the case, it can’t get air in its tank and as a result, it gets vapor locked. It prevents fuel flow to its carburetor, consequently stopping the engine. To get it right, try loosening the gas cap. Now, crank the engine.

Why My Starter Keeps Turning Off?

It’s an indication that shows that your starter motor receives inadequate electricity. A few of the possible causes can be the weaker batt

Ian Haynes
Ian Haynes

Ian Haynes is a digital marketing specialist and has successfully written hundreds of home improvement guides. Outside of his work, Ian likes fixing old bikes and exploring Brooklyn with his Labrador.

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