How to Start a Lawnmower with a Bad Starter?


All homeowners with lawns know pretty well that lawnmowers are unmatched machines for tending your yard. But it is only fun when the mower is working fine and smooth. When a mower is not running correctly or having problems, mowing becomes tedious and rather unenjoyable. Lawnmowers, like all machines, run into all sorts of issues. But could there be a more frustrating problem than the mower not starting at all? One of the reasons for this could be a bad starter. But don’t worry, even with a bad starter, there are ways to start your mower.

How to Start a Lawnmower with a Bad Starter:

  • Clean the battery leads and seal any leakages, then try again. Replace the battery if it is faulty beyond repair.
  • Bypass the solenoid and start the mower using the starter motor only.
  • If the starter motor is faulty, you’ll have to get a new starter motor.
  • Replacing the entire starter with a new one is better than replacing just the motor.
  • In case of a faulty ignition switch, try to make its connections tight. If it is defective beyond repair, get a new ignition switch.

Reasons for a bad starter:

The starter is responsible for using the energy of the battery to start the engine. A bad starter won’t do this job, and the ignition system won’t get any energy, which means that there will be no spark and the engine will not start. A starter can go wrong because of these causes:

  • A flat or faulty battery
  • Faulty solenoid
  • Faulty ignition switch
  • Faulty starter motor

The final solution to a bad starter can be to replace one or more parts, but techniques like bypassing the solenoid can let you start the mower for now, and you can do the replacement later. To do that, you’ll need to get some basic information about a starter and its working. This article will surely help you in this regard.

What is a Starter?

The starter is an essential component in a lawnmower that transfers electricity from the battery to the ignition system, thus allowing the engine to start. A starter has two main components, a starter solenoid, and a starter motor.

● Starter Solenoid:

Solenoid gets current from the battery and transfers it to the motor. When the ignition button is pushed, a current is sent from the battery to the solenoid through the wiring and then from the solenoid to the motor.

● Starter Motor:

The starter motor is the starter component that is linked directly to the spark plugs. It sends current from the starter to the engine.

These two components are independent but work together to power the spark plug so that a spark can be generated in the combustion chamber, producing power from fuel. Though the starter solenoid and motor are independent, the chain is disrupted if one fails, and the engine won’t start when you push the ignition button. But because these two components are separated, the mower can still be turned on if one goes bad.

Before making any repairs or changes, you need to know what’s wrong. A lawnmower with a bad starter will show specific symptoms that can help you see the problem’s root cause.

Symptoms of a Bad Starter:

A satisfying rumble sound is always expected when starting the engine, but a mower with a bad starter will make abnormal sounds when it is being started. The sounds can be used to judge the nature of the underlying problems.

● Abnormal Solenoid Clicking:

When the ignition button is pushed, the solenoid transmits an electric spark that starts the motor. The motor starts rotating a smaller gear that engages with a larger gear of the engine. This is how the engine is jump-started. When this process goes normally, a clicking sound is produced, followed by a whirring sound that indicates that the starter motor is engaging with the engine.

If you push the ignition button and only the clicking sound is produced, it is a sign that something is wrong and the motor is not engaging with the engine’s gear.

● Whirring sound, but no Catch:

When the whirring sound is produced but is followed by a loud rumbling sound, it is a sign that the starter is not engaging with the engine in the normal manner. This is a sign of the starter’s smaller gear not correctly engaging with the engine’s gear. Another sign of this issue is when the engine starts but stops after just a moment. Broken teeth basically cause these problems on the starter motor’s gear or worn motor brush brushes. If this is the case, these faulty components will have to be replaced.

● Not Starting Even with a Fully Charged Battery:

If your mower does not start even though there is no battery-related issue, it is the clearest and obvious indication that the starter isn’t working fine. When this happens, start looking for the cause of problems right away.

● Solenoid Not Clicking:

If there is no solenoid clicking sound when you push the ignition button, it is an indicator of loose connections to the solenoid. This means that the current is not reaching the solenoid. If this is the case tightening solenoid connections will get your mower running.

Starting a Mower with a Bad Starter:

A bad starter is caused by electrical problems that can be fixed. Here’s a guide on how to do that.

● Flat or Faulty Battery:

The first thing to get in order when your mower is not starting is the battery. If the battery fails to provide electricity, there is no way your mower will start.

Start by looking for leakages. Charge the battery with a charging cable, and if it becomes wet, then the battery is leaking. Small leakages can be sealed, but if the leak is too big, replace the battery. When dealing with leaks, wear safety gloves and glasses to avoid acid burns.

Check the battery voltage too. The battery voltage should be 12V. If the voltmeter reading is less than 12.4V, it is a sign of a faulty battery that needs to be replaced.

● Ignition Switch:

Loose connections of the ignition switch wire or corrosion on the back part of the switch can also cause a bad starter. If the issue is not of a severe nature, you can fix it yourself. If the ignition switch has become so bad that it can’t be repaired, it should be replaced with a new one.

● Solenoid:

The starter solenoid is a mounted switch that provides current to the engine’s starter motor. The solenoid has four threaded electrical lugs connected to the battery, ground, ignition switch, and starter motor.

Different lawnmower models have their solenoids at different locations. You can locate the solenoid in your mower by following the red battery wire. After locating the solenoid, check its connections and screws and tighten them using a wrench or a plier. Rotate the ignition key. If the solenoid clicks without starting the mower, the solenoid needs to be replaced.

● Starter Motor:

The starter motor is attached to the crankcase of the engine. If you have already checked the components mentioned above and they are fine, but your mower is still not starting, the chances are that its starter motor is faulty.

To check the starter motor, connect it to the battery using a jumper cable while attaching a negative terminal screwdriver. You’ll see some sparks, but there is no danger of shock from a 12V battery. If the motor doesn’t start and gives clicking sounds, the motor is faulty.

Sometimes the winding, magnet, brushes, etc., inside the mower can get dirty or burn during use. Fixing them can solve the issue too.

A faulty motor can be rebuild. But this has to be done by a professional electrician.

Bypassing the Solenoid:

Like said before, the starter solenoid and motor are two independent components. If you have determined that only the solenoid is faulty, you can try to start the mower using the starter motor only.

A solenoid has wire connections from the battery/ignition switch. To bypass the solenoid, connect these wires to the motor using a metallic connection. Then try to start your mower. If it produces a whirring sound, it means that the mower can be started. You’ll need to try a couple more times to start the mower.

Use protective equipment while bypassing the solenoid.

Final Remarks:

The lawnmower not starting on a potentially enjoyable mowing day is very frustrating. Mowers fail to start when their starters go bad. But most of the time, starter problems are not too complicated and can be fixed by the user. Follow the guidelines mentioned in this article to get your mower running once again. Checking other electrical components such as spark plugs will help too.

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