Tag: lawn mower won’t stay running

Lawn Mower Repair Tips

My Lawn Mower Will Only Run on Full Choke

To understand this problem, you must understand a little about how a carburetor works.

When you place the choke in the on position, it creates more suction on the throat of the carburetor which creates more vacuum to pull fuel out of the main jet and up through the emulsion tube which mixes air and fuel. The idle circuit could also be in play during this start up. An engine needs a slightly richer or more fuel than air mixture when it starts.

As the engine is running and the choke is slowly released to open, less vacuum is created and less fuel is then drawn out of the main jet as the engine is brought up to speed.

What happens is fuel becomes a solid state as it evaporates and this plugs up the emulsion tube and the idle jet. If that happens the symptoms of only running on full choke will be present. At this point the carburetor needs disassembled and thoroughly cleaned of any fuel deposits that have accumulated. Then it will need to be re-assembled and tested to ensure that the carburetor cleaning did its job in fixing the my lawn mower will only run of full choke problem.

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Lawn Mower Repair Tips

My Lawn Mower Dies After Starting

This is one of the most common problems you can have in the early spring when you pull out the lawn mower for the first time. The mower will run for a few seconds and then it will die as if you shut off a switch.

Most of the time this is caused by not using a fuel stabilizer like Ethanol Shield  or Stabil . When your gasoline or diesel fuel is stabilized, it prevents the fuel from phase separating into different parts and then drying up while inside of a carburetor or fuel injected mower. Once dried up, they plug up those vital ports that allow the engine to continue to run. Just enough fuel will enter the engine to start but the full throttle it needs to run will happen because the engine is starving for fuel.

The carburetor will need disassembled to clean all the ports properly. In some cases you can remove the float bowl screw at the bottom of the bowl and clean out the main jet that is in that screw. On Chinese and Japanese lawn mower engines, the idle jet must be cleaned in addition to the main jet and emulsion tube which is inside the fuel tower that runs vertically through the carburetor.  The idle jet is located inside a plastic plug that is held in place by the idle speed control screw that is also plastic. The idle jet has a very small port size so use something like one strand of wire from a small electrical wire.

Use carburetor cleaner to spray out all the ports and then blow them out with low pressure compressed air. Re-assemble the carburetor and install and test to see if it works as it should. It is runs but surges, you still have a blockage somewhere in the carburetor that will need to be cleaned. Repeat the process until you find that port that is blocked. You could also have an air leak and may not have the bolts that hold the carburetor tight enough.

Make sure you have fresh fuel in the engine as well because stale fuel will not light off very well or produce the power you need to keep the engine running. By cleaning your carburetor, you will fix the problem of my lawn mower dies after starting.

Lawn Mower Repair Tips

My Lawn Mower Will Not Stay Running

This is another frequent problem with a lawn mower. It will run for a while and then dies. It could run for a few seconds or it could run for 30 minutes and decide to conk out. It really doesn’t matter to you of course as you want it to keep on running!

A few things you can check is to make sure your fuel is good. Your mower needs clean and fresh fuel to run. If you can take a fuel sample, it should be clear, not have any discoloration other than a slight yellowish color and not have any debris or particles in it. The odor should be strong and not stale.

If you determine that your gas is bad, it will need to be removed from the carburetor and the fuel tank and fresh fuel added.

Another problem is a carburetor that is plugged up. It will run on choke but when it transitions to the main jet, it will stumble and die because it is not getting fuel through that jet. Cleaning the carburetor is the solution for this problem.

Your choke could be stuck closed and cause the mower to run for a short period of time and then die. You can tell this by looking at the open end of the carburetor and seeing if the butterfly is closed or if it is opening as the engine warms up. A stuck choke will cause your lawn mower to not stay running every time.

The last thing is the ignition system. Your ignition coil could be heating up and malfunctioning. When an ignition coil breaks down, it will stop producing power to the spark plug and it will die at that point.

By checking these items one by one, you can narrow down what the problem is and get your lawn mower running once again.