Bad Ignition Coil Symptoms Lawn Mower- 5 Common Ones

by Jack Grover
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Bad Ignition Coil Symptoms Lawn Mower

Bad ignition coil symptoms for riding lawn mower include: hard to start, the engine only runs when you wiggle the plug wire, and poor performance indicating that your lawn mower’s ignition coil needs to be replaced. Replacing an ignition coil is pretty simple as long as you have some basic tools handy.

Today you are going to learn with us about the bad ignition coil symptoms of lawn mowers. We will discuss when a lawn mower coil goes bad, common symptoms and how to solve these problems.

Let’s dive into this.

Bad Ignition Coil Symptoms Lawn Mower

Let’s have a sneak peek on the most common symptoms and their solutions first.

SymptomsReason Behind the ProblemSolution
The lawn mower’s motor overheats after only a few minutes of mowing, causing it to shut downBad ignition coilIgnition coil needs replacement
The mower does not shut down until the spark plug is disconnectedA faulty ignition switchThe switch needs to be replaced
Lawn mower starts then diesCarburetor with a filthy or clogged carburetor bowl
Rubbish leftover from outdated gasoline.
Your reservoir is too full of oil.
Overheated lawn mower ignition coil
Use carburetor cleaner
Remove the old gasoline and fill with a fresh one
Use a siphon to drain some oil
Ignition coil needs replacement
The lawn mower comes to a halt halfway through the jobGlass gets clogged up in the deck Bad lawn mower ignition coilAdjust cutting height and
change the lawn mower coil
Engine cranks but won’t startCarburetor may not be getting enough fuel
Carburetor may be clogged
Spark plug or disconnected wires
Fill the tank with fuel
Clean the carburetor
Replace plug or wires

Symptom 01: Lawn mower ignition coil overheating and causing immediate shutdown

Well, this is the most common symptom of a bad ignition coil. To ensure this, try the following steps

  • At first, remove the spark plug boot from the spark plug and replace it with the spark tester’s boot.
  • Connect the tester’s free end to the original spark plug boot. Push it in firmly to ensure a solid connection.
  • Turn on the mower when it is cold and look through the tester’s window. There is a typical spark that allows the mower to operate, as you can see.
  • Remove the spark plug boot and replace it with the original one. Startup the engine and replace the tester. Mow some grass to bring your lawnmower up to operating temperature so that it will stop by itself.
  • Replace the old wire with the in-line spark tester and try to start it. If you find no spark, check for the same level of spark as when the mower was cold. The ignition coil is faulty if there is little or no spark. If the spark is still good, but the mower won’t start, it’s not a result of the ignition coil.

Symptom 02: The mower not shutting down

The problem can be with the ignition switch. Let’s check.

  • The ignition switch is simple to fix. Set your multimeter to check for continuity.
  • Attach the meter leads to the ignition switch terminals. The multimeter should display continuity if the control bail is left in the off position, and there should be a circuit via the switch.
  • To check for continuity, remove the control bail from the run position. The multimeter should show no continuity in this situation.
  • If the continuity test is failed, the switch will need to be replaced.
  • It’s a simple replacement to replace the ignition switch. Remove the wires from the switch one at a time. Remember to label each wire as you remove it so that you can reattach them in the correct locations.
  • Remove the switch from the engine now.
  • Place the new switch in its location. Then, adjust the switch or the switch actuator so that it makes good contact with the switch.
  • Reattach the wires to the new switch once it’s in place.

Symptom 03: Lawn mower starts then dies

Sometimes, a bad ignition coil, along with some other reasons, can cause this issue. So, we have found 3 separate solutions for 3 separate reasons. You will find the solutions below:

Solution for clogged carburetor bowl

Remove the carburetor bowl, give it a good cleaning, and then reassemble it. Clean the screw and hole with a carburetor cleaner as needed.

Don’t over-tighten the screw when reattaching the bowl. These problems, as well as other faults that may be caused by poor maintenance and lack of lubrication (for example, a seizing engine), might cause the threads to become stripped enough to distort the seal.

Solution for outdated gasoline

If you find the mower tank less than half-filled with previously used gas, it’s a good idea to add new gas to lower the contaminants. If the old gas is more than half of a tank, it’s best to suck it out and fill the tank with new gasoline.

Solution for reservoir full of oil

You can simply drain out excess oil if you have too much. If you have a walk-behind mower, you may use a siphon to tip it over and remove the oil from the aperture where you add it.

Solution for overheated lawn mower ignition coil

See our solutions for ignition coil replacement on Symptom 01.

Symptom 04: The lawn mower comes to a halt halfway through the job

Raise or lower the cutting height of your mower as needed. If you try to mow too much grass, the mower may stall and stop working due to clogged glass in the deck.

The ignition module is another option. Your coil for lawn mower may be faulty. You can’t restart your mower if it’s still hot, right? If you have to wait for the mower’s engine to cool before starting it, the ignition coil for lawn mower is most likely broken. Just replace the ignition coil.

Symptom 05: Engine cranks but won’t start

So, when you find the engine cracks but won’t start, at first, make sure the tank is full. If the level is too low, the carburetor may not be receiving adequate fuel.

If the fuel level is correct, however, there’s a good possibility it’s a blockage. At this point, you should take out the carburetor and clean it. We also recommend checking the fuel system for any blockages or leaks.

After that,

  • Double-check the throttle/choke to ensure it’s in the correct position. You can usually discover this information in your owner’s manual.
  • Finally, spark plugs or disconnected wires could also be the reason. The spark plug is important for the engine to operate, and any issues with it may cause a range of engine problems. Check the spark plug and ignition wire to be sure they’re in good working order.
  • If none of this works, you should take it to your local small engines repair shop for inspection and repair.

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Frequently Asked Questions (FAQs)

Can you tell if an ignition coil is bad?

If the lawn mower has an overheating issue, engine misfires, is hard to start, or sudden backfires, then we can tell, the ignition coil is bad. In this case, the ignition coil needs to be replaced. If you can follow our procedure above then you can fix the problem, otherwise, go to your local repairing shop for quick solutions.

What does a coil on a lawn mower do?

The ignition coil is in charge of converting the battery’s voltage into a spark, which ignites the mower’s engine. When you start your lawn mower, the flywheel and its magnets pass through the coil, generating a spark. The flywheel continues to spin, the magnets pass by the coil, and the spark plug fires at a specific time as long as the engine is running.

u003cstrongu003eHow do you test a lawn mower coil?u003c/strongu003e

First, remove the ignition coil. Then test the coil with a multimeter or with an Ohm-meter. If the coil is not ok, then replace it with a new coil and test the lawnmower with a new coil.

How do you know if the ignition switch is bad on a riding lawn mower?

If the mower is not shutting down until the spark plug is disconnected or the engine cranks but won’t start, then we can know that the ignition switch is bad on a riding mower.

Conclusion

The bad coil symptoms may be more noticeable or less apparent depending on the type of mower.

Weather conditions and the way you maintain your tractor also affect bad ignition coil symptoms lawn mower.

A bad ignition coil can cause misfires, bad engine performance, and bad gas mileage if it is not replaced.

If you notice bad coil symptoms on a lawn mower, you should take your mower to the repair shop for a bad coil replacement immediately.

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