Turning on… The starting point and a fundamental requirement for any lawn mower to be worth its weight but yours isn’t? There are a couple of reasons, few all too tough to correct, that could be causing your lawn mower to hesitate or even refuse to start altogether! Let’s take a look at some of the possibilities and determine what might be causing your problem today. 

Start with safety. With any lawn mower or small engine work, if there is a battery it should be disconnected as a precaution. This ensures there’s no power running to your equipment. If there isn’t a battery you should pull the spark plug wire. And in cases where you are working directly on the engine, you should disconnect both.

Is this the start of the season? 

Some of the most common causes of staring issues are tied directly to improper winterization or prepping for the new spring season. If you can confidently say you either prepared your mower for the winter or had it winterized by professionals, then skip on. If you can’t, no worries, there are a few things you can quickly check to see if you’re starting issue is one you can fix at home!

• Battery

Over time batteries die. A clicking sound is your first indicator that yours is on its way or already there. If your battery is the case, it means your mower is trying to drag electricity from it and not getting what it needs in return resulting in a no-start. Disconnect the old battery from the terminals and replace it with a fresh one! 

• Oil

Make sure your unit has oil in it prior to the first start. Often a mower won’t start due to the low oil pressure sensor and that’s a simple fix. Before you start your mower the first step should always be a fluids check. Oil and gas are your number 1 concerns. If you do forget and your oil is low, be sure to top it off and try to start your mower again! 

• Old Gas

How long has the gas been sitting in your mower? Chances are if your mower has had gas in it for the winter season or even over a month, that gas may be bad. 

How much gas is in it? If it’s a very small amount left, likely you can fill it with fresh and get it running. Any more and you want to siphon it out. Technically speaking, all the old gas should be removed but if that isn’t an option, mixing in fresh is a choice you can make.

Electric mower? No worries, your equivalent to gas is the cord or battery and it’s actually easier to check! See if your cord is damaged by looking for any fraying, kinked, or otherwise damaged sections. If you see anything worth noting, you may be in need of a new cord and would need to consult a local shop to have it safely repaired. 

• Filters

There are a few! The first stop is the air filter. The most common piece to regularly replace on your lawn mower, aside from gas anyway. The air filter is constantly taking in air from outside, often with grass, dirt, and particles mixed up in it. They get dirty and as such need to be cleaned often. Depending on the size of your mower you may even have two layers, likely cocooned within one another. This requires removing the plastic housing, and gently blowing out or wiping off your filter. If you’re unsure of where the filter is located consult your owner’s manual or search the model online. If the filter is bad enough, you may need to replace the filter altogether. Consult your local repair shop to get the right part right away!

No luck? Let’s go back to the fuel… filter that is. The fuel filter is what keeps your engine running with no contaminants from the gas you put in it going into the carburetor. These particles often come from the manufacturing process, the housing container, or even the pump itself but your filter stops it from being a problem. Too many contaminants over the years build up in the carburetor and stop the engine from getting enough clean gas regardless. How to tell if that is the issue or not is an easier task than fixing it. If you’re an avid DIYer and are up to the task, be sure to follow all recommended safety and installation guidelines or just drop it at your local repair shop for a quick fix! 

If the mower is stalling, sputtering, or idling rough these are telltale signs it may in fact be the filter. Start by checking your owner’s manual for the locations of the filter. This will help determine if you should clean or replace the filter. Some filters have a longer lifespan than others and might be able to be cleaned prior to needing a full replacement. If you’re unsure or need assistance contact your local repair shop with your make and model and they will have the answer for you. 

• Spark Plug

If the engine sounds like it’s struggling, misfiring, or stalling your spark plug may be the tiny but mighty reason! First, we can see if it’s as simple as a loose plug. If that’s the case, congrats you won the “no start lawnmower” lottery. Simply push the spark plug in until you feel it has a tight fit. 

Cleaning and replacing are the other alternatives to making it a happy plug. When the spark plug acquired build-up over time from the mower it halts the transfer of electricity. When this happens you can start by disconnecting the plug wire and with a wrench remove the spark plug. Using a rag or a wire brush gently clean off any excess residue and carbon then re-install. When all loss fails replacing the plug altogether is a simple fix for any vid DIY-er.

• Carburetor

They make a spray for that… but it’s never that easy. The carburetor itself is simple in theory but may take some digging to find. Like any engine, it’s all connected. Gasoline goes through a fuel filter and air in through the air filter mixing in the carburetor to be turned to create power through the engine. What happens though when things that aren’t supposed to go into the carburetor do? Problems occur. Like any old part, they can just go bad and might need cleaning or fixing to get them back up and running. If you’ve tried it all and still think it’s just not getting the juice it needs, have your local shop check out the carb!

Is it sudden?

Let’s check the deck! Your deck protects you and all things above the grass from the blades, but sometimes they also keep the cut grass safe from the lawn bag too. Grass and debris can get caught and build up under the deck. This can cause the blades to become jammed and spin unevenly or not spin altogether. 

With all safety precautions in mind, be sure the mower is off with no chance of power running to it. If it’s a push mower you can turn it over or safely jack up a riding mower. To help make the process easier, you can raise the deck to full height as well. Check and see if there’s any obvious clogging and remove the excess grass and debris with a stick, tool, or rag.

Safety switches in check! For a mower to start all safety switches must be functional. This may be a sign your mower is having permissive or electronic issues. This is more common than not that a simple switch is flipped and keeps your lawn mower from starting in an attempt to keep itself and you in safe operating condition. You can call your local repair shop to have someone come out and test your switches to determine if that’s the case for your equipment.

Consult the professionals!

All is not lost! If you don’t think any one of the above problems is the culprit then it could be a bigger issue. Parts like the starter, ignition switch, and electronic issues are even more in-depth repairs that could be keeping you from a fresh-cut lawn. Where its always a safe bet to just take it into a shop is when you see any one of the more dangerous signs below.

• Smoke- If you see smoke chances are there’s more going on than you think. While white smoke is a sign of oil issues, first check if there’s enough oil in it! Black smoke is a different beast altogether. This could be a sign of a bigger engine-specific issue. 
• Weird sounds- if you hear rattling, knocking or any other haywire noises it’s best to play it safe and not run the mower. A loose blade could be hazardous to you and a problem in the engine could cause even more damage with operation. Consult a professional and run the sound by them before digging too deep.
• New movement or vibrations- Right in line with sounds, a shaking lawn mower can be a sign of something small or big that just is not right. For the safety of yourself and the machine, consult a professional right away.