Troubleshooting a Lawnmower That Won’t Start – What to Check


You finally work up the motivation to mow your lawn. You put on your sunglasses, plug in your headphones with mowing jams playing, and then, it happens. The lawnmower doesn’t start. And you’re left trying to figure out how to start it before your perfectly good motivation runs out!

Sound familiar? If your lawnmower won’t start, there are a couple of things you can check before you give up or head to a mechanic:

1. Out of gas

As simple as it might sound, your lawnmower might just be out of gas! Someday in 2070, mowers will come with fancy fuel alarms, but until then, if your mower refuses to start, fill her up and see if she’ll run.

2. Fuse box issues

As you troubleshoot your dead mower, be sure to check the fuse box. There may be a short or a broken fuse. Unlike your fuse box at home, fixing your mower’s fuse box isn’t as simple as switching it “off” then “on” again. It’s either shorted out or completely shot.

3. Electrical problems

When your mower won’t start, there’s a chance it’s the electrical section’s fault. There are three things you should check in this section:

A. The spark plugs: Check the connection of the spark plugs by disconnecting and re-connecting your spark plug wire. You should hear or feel a CLICK sound upon reconnection.

B. The starter: Check the connections leading to the starter to make sure the starter is connected to the engine. Also, LIGHTLY tap the starter using a screwdriver while you ignite. If the mower starts while you’re LIGHTLY tapping the starter, replace the starter.

C. The battery: Just like a car, if your battery is dead your mower will be too. Use a multimeter to check the battery power, and check the positive and negative (+ and -) node connections for corrosion and/or a loose connection.

4. Clogged air filter

If your lawnmower engine sounds like it’s trying to start but then sputters off like it’s giving up, it might be that the air filter is clogged. Simply look at your air filter, and if it’s clogged, use an old toothbrush or compressed air to brush/blow the gunk out. If the filter is really dirty, replace it altogether.

5. Obstructed blades

Your mower engine has to be able to suck air in order to work properly. So if something is blocking it, your mower may not start. Check the blades for anything that might be clogging or jamming them like weeds, wet grass, or twine.

As you attempt to revive a lawnmower that won’t start, be sure to check your owner’s manual, online forums, YouTube, etc. for more troubleshooting tips. Most manufacturers have digital manuals for their mowers on their website for free; just use your model and serial number to look yours up. Of course, if you’re not able to nail down the issue and fix it yourself, take your mower to a repairman or a mechanic for further inspection.