Riding Lawn Mower Won't Start (Causes and Fixes)

If you're like most people, you rely on your lawn mower to keep your lawn looking neat and tidy. But what happens when your mower won't start?

Troubleshooting lawn mowers is fairly straight forward, there are several reasons why your lawn mower might not start.

One of the most common causes is a dead battery. Another common cause of starting problems is a faulty starter motor.

Other issues that can cause mower starting problems include loose or corroded battery cables, a bad solenoid, a fuel delivery issue or a faulty ignition switch.

Common Causes of Lawn Mower Starting Problems

In no particular order, here is a list of lawn mower starting problems I encounter in my small engine repair shop fairly often.

Check the Carburetor

Take it from me, in my 25+ yearsd or small engine experience I've found that a dirty or clogged carburetor is one of the most common causes a mower won't start.

I wrote a lawn mower carburetor cleaning guide to help you resolve this issue if you suspect a dirty carburetor is the culprit preventing your lawn mower from starting.

Dead Battery

If your lawn mower battery is dead, the starter will not work. You can check the battery voltage with a multimeter to see if it is charged.

If the battery is not charged, you can try jump-starting it with another battery or charging it with a battery charger.

Dirty or Faulty Spark Plug

A dirty or faulty spark plug can also cause starter problems. If the spark plug is dirty, you can clean it with a wire brush.

If the spark plug is faulty, you will need to replace it with a new one. Make sure to use the correct spark plug for your lawn mower model.

Clogged Fuel Filter

A clogged fuel filter can prevent fuel from reaching the engine, which can cause starter problems. You can check the fuel filter for debris and replace it if necessary.

Refer to your lawn mower manual for the location of the fuel filter.

Faulty Ignition Coil

A faulty ignition coil can also cause starter problems. You can check your mower ignition coil with a multimeter to see if it is working properly.

If the ignition coil is faulty, you will need to replace it with a new one.

Worn Starter Gear

If the starter gear is worn, it may not engage properly with the flywheel, which can cause starter problems.

You can check the starter gear for wear and replace it if necessary.

Loose or Corroded Connections

Loose or corroded connections can prevent the starter from working. You can check the connections for corrosion and tighten them if necessary.

Make sure to disconnect the battery before working on the connections.

Lawn Mower Starting Problem

Troubleshooting Lawn Mower Starting Problems

If your lawn mower won't start, the starter may be the culprit. Here are some common troubleshooting steps to help you diagnose the problem and get your mower running again.

Check the Battery

The first thing to check is the battery. Make sure it is fully charged and that the terminals are clean and tight.

If the battery is weak or dead, the starter won't have enough power to turn the engine over. You can test the battery with a multimeter to see if it is holding a charge.

Inspect the Spark Plug

Next, inspect the spark plug. If it is dirty or fouled, it may not be providing enough spark to ignite the fuel.

Remove the spark plug and clean it with a wire brush or replace it if necessary. Make sure the gap between the electrodes is set correctly.

Clean or Replace the Fuel Filter

A clogged fuel filter can prevent fuel from reaching the engine, causing starting problems. Check the fuel filter and clean or replace it if necessary.

You can also check the fuel lines for any cracks or leaks that may be preventing fuel from reaching the engine.

Test the Ignition Coil

The ignition coil is responsible for providing the spark that ignites the fuel in the engine. If it is faulty, the spark may not be strong enough to start the engine.

You can test the ignition coil with a multimeter to see if it is producing the correct amount of voltage.

Inspect the Starter Gear

Finally, inspect the starter gear for any damage or wear. If the gear is damaged, it may not be engaging properly with the flywheel, preventing the engine from turning over.

You can remove the starter and inspect the gear for any signs of wear or damage. If necessary, replace the starter or have it repaired.

By following these troubleshooting steps, you should be able to diagnose and fix most lawn mower starter problems. If you are still having issues, it may be best to take your mower to a professional for further diagnosis and repair.