Lawn Mower Won’t Stay Running: Why And How To Solve?
So, your lawn mower keeps dying on you. Well, just like anything with a motor, sometime your mower will have issues that cause it to stall and cut off. If you are having that issue with your mower, then you are in the right place.
In this article, we will look at the reasons why your mower might not stay running and also give you the solutions for them. Keep reading to see all the possible reasons why your lawn mower is stalling.
More: If you must replace the battery for your lawn mower, this is the best lawn mower battery for you.
Before going into an in-depth analysis of each issue, we will list out the potential problems below. That way if you have an idea of what the issue might be you can jump to that section first to save yourself some time.
The reasons why your mower might not stay running can fall into the following areas:
- The Fuel System
- The Carburetor
- The Ignition System
- The Cutting System
1/ The Fuel System
There can be a variety of reasons with the fuel system why your mower might be cutting off. Most of them are pretty simple things and can be fixed easily. The first thing to check with the fuel system is the gas.
If you left gas in your mower for an extended time, then it might not be good any longer. It could have had water condense in it, or it could have evaporated leaving a varnish-like residue.
If you know you left gas setting, then drain the gas from the tank and also the carburetor, then you can add fresh gas. This might solve your problem.
Some of the other issues in the fuel system, which we will cover shortly, can also come about from leaving gas in the system, so it is a good idea to drain the gas if you know that you won’t be cutting for a while.
The next thing that could be wrong with the fuel system that can come about from old gas or happen on its own is dirt and gunk build up. Gunk and deposits can build up in a variety of spots.
The first spot to check is the gas cap itself. Remove the gas cap and see if the mower will stay running without it. If it does, then that means the gas cap vent is blocked.
You will need to clean it out, so air can get thru. After doing that the problem should be resolved. If something else is dirty though and the gas cap is not the issue, then you will have to look farther.
Sticking with airflow, the next thing you can check is the air filter. This should be clean and not have debris or blockage. Also, if it has oil in it, then that is a problem too. If it does have a blockage or is dirty, then you will need to clean it out or replace it.
Air filters are not expensive, so it is a good idea to replace with a clean one regularly or at least clean it out since it is easy to get too. If it is not the air filter that is dirty, then it might be the fuel lines that are dirty.
If that is the case, you will have to drain the fuel and then remove the lines. Remember to drain both the tank and the carburetor. When removing the lines inspect them and see if you see any build up. If you do clean it off or replace the lines.
2/ The Carburetor
The issue may be in the carburetor itself though. It might be the thing that is dirty. If you are draining the fuel, then go ahead and take the time to check the carburetor. See if you can see any build up of gunk or deposits in it.
If you do be sure to clean it. Also, remove the fuel filter from the carburetor and see if it is dirty. If it is then clean or replace it as well. Same as the air filter, the fuel filter is pretty easy to get to and is cheap, so stay on top of replacing it and making sure it is clean. This will keep other parts of your mower running longer.
When cleaning the carburetor, it is essential to do it properly. You should use carburetor cleaner and spray it down thoroughly. Sometimes though even the cleaner won’t be able to get all the build up off. This is because fuel residue can be hard to remove.
If you can’t get the carburetor clean, then you can rebuild it with a kit from your mower manufacturer. Sometimes though it isn’t worth it to rebuild. This may be because you don’t have the time or the skills to do it.
If that is the case, then you can just buy a whole new carburetor and replace the old one. No matter if you are cleaning, rebuilding, or replacing the carburetor be sure to clean out the fuel lines as well.
3/ Ignition System
The next reasons why your mower might not stay running could come down to the ignition system. This is similar to the fuel system and could be lumped in there. The ignition system for our purposes is where the spark occurs to ignite the fuel and provide power to the mower.
The part of the ignition system that we are worried about is the spark plugs. Old wore out, and dirty spark plugs can lead to the engine dying. They may work good enough to start the mower, but then misfires might start to happen leading the mower to shut off. If you hear misfires, then checking the plugs should be one of the first things you do.
To make sure the plugs are good you first need to pull them from the engine. Next, you can visually look at the electrode. If it looks dirty, then you can try cleaning it with an emery board, but if the electrode is already too thin, then you will need to replace that plug.
Also, it is a good idea to replace all the plugs if you are replacing one, so you know that they are all good. The electrode might not be dirty though, but the problem could still be the spark plug. If the gap on the plug is too big or too small than that can be an issue too.
You will need to look up the specifications for your mower and the gap it should be and then use a gapping measure to measure the gap. If it is off, then you need to replace the plugs.
4/ The cutting system
The last area that can cause your mower to stall while mowing is in the cutting system. What we mean is if you are cutting thick or tall grass, then it might be bogging down the blades and causing the engine to stall.
If you can tell that the mower is having trouble cutting on the level you have it set too, then you will need to raise the deck. If raising the deck doesn’t help, or the grass isn’t that tall or thick, then the problem might be in the blades themselves or under the deck.
If the blades are dull, then they will not cut well, and that can lead to the mower stopping. You will need to get under the deck and remove the blades to sharpen them. Once they are sharp, that should solve the problem.
If your blades are sharp though, then they might be getting bogged down for another reason. That other reason is you could have a lot of grass built up under the deck. If that is the case, you will need to get under it and clean it out.
If you are sharpening the blades or cleaning the deck, then you should go ahead and do both things since you are already under there. It doesn’t take that long to remove the blades to sharpen them if you are already cleaning under the deck and it doesn’t take that long to clean under the deck if you are already sharpening the blades.
By doing both, it will save you time later and make sure you get the best cut possible.
One thing to check is lawn mower battery, if it is weak, the best battery tender is the excellent tool to recharge your battery.
So, after reading this, you now know all the possible reason why your mower won’t stay running and also the solutions for them. The issue could be in air flow or fuel flow. In either case, you will need to clean those systems out.
It can also be due to bad ignition. If that is the case, you will need new spark plugs. Lastly, it might just be that the blades are dull, under the deck is dirty, or the grass is too thick and not be a mechanical issue at all. If it is from that, then you will need to sharpen the blades and clean under the deck or raise the deck.
Luckily most of the reasons why your mower is stalling are easy fixes if you know what to check, and now that you have read this you do, so you are well on your way to fix your mower that is dying and not has to worry about the engine stopping in the middle of cutting again.