Your Simplicity mower may start to run sluggish, act like it’s almost going to die or actually die. While this could be the result of many different problems, these symptoms point to a lawn mower not getting the gas it needs to stay running.
A Simplicity lawn mower isn’t getting gas when old fuel clogs and degrades fuel components; the fuel filter is plugged; the fuel lines are clogged; the fuel pump is bad; the carburetor is dirty; or the fuel cap vent is plugged.
Before you begin troubleshooting your Simplicity mower, follow all safety precautions outlined in your operator’s manual.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
6 Reasons Your Simplicity Lawn Mower Isn’t Getting Fuel
Most gasoline today contains ethanol, a corn-based fuel, to make gas more environmentally friendly. Ethanol naturally attracts moisture from the air.
This water and ethanol mixture can leave behind gummy deposits restricting fuel flow. This solution can also cause premature failure of the fuel components.
Gas can break down and become less effective as quickly as 30 days after purchase. Find out more about the right gas to use in your Simplicity lawn mower in this guide. I further explain the effects of ethanol along with tips to stabilize fuel and reduce moisture.
FIX: Use a siphon to drain the old fuel from your tank. Collect the fuel in an approved fuel container so you can later recycle it. Add fresh fuel along with a fuel additive to stabilize the fuel, reduce moisture and clean the fuel system.
I use Sea Foam Motor Treatment in my lawn mower. You can read more about the advantages of Sea Foam here.
Plugged Fuel Filter
A fuel filter is installed on a Simplicity lawn mower to strain dirt and sediment from the fuel before it enters the fuel system. A fuel filter can become plugged preventing gas from passing through the filter.
I recommend replacing the fuel filter annually when completing a full service of your Simplicity lawn mower.
FIX: Replace your fuel filter when you find it is clogged. You will find an arrow on the side of the filter. The new filter must be installed with this arrow pointing in the direction of your fuel flow.
Clogged Fuel Lines
Gummy deposits left behind from running old fuel can prevent fuel from flowing through the fuel lines. When this happens, your Simplicity will not get the gas it needs to start and run.
To find a clog in the fuel line, you will need to check each section of the fuel line.
FIX: Start and stop fuel flow using the fuel shut-off valve located at the bottom of your fuel tank. You can also use hose pinch pliers to clamp the line and stop the flow. Check each section of the line by starting and stopping the flow to see if fuel is still running out of the hose.
Once you find a section of the line that is clogged, remove the line from your mower. Spray carburetor cleaner into the line to help loosen the clog. Blow out the line with compressed air. Repeat until you dislodge the clog and open the line.
If you are unable to unclog the line or the fuel line is dry and cracked, it’s time to replace your fuel line.
Bad Fuel Pump
A Simplicity lawn mower requires a fuel pump when the carburetor is positioned higher than the fuel tank. Fuel cannot flow uphill without the use of a fuel pump.
Most Simplicity mowers use a vacuum-style fuel pump that builds pressure off the crankcase to get fuel to the carburetor.
When the fuel pump cracks or fails to work correctly you will have to replace it. If you don’t see physical cracks or fuel leaking, you must take some troubleshooting steps to isolate the problem in your fuel pump.
FIX: Before you check your fuel pump, check to make sure you are getting fuel to the fuel pump. You may have completed this step already if you checked your fuel lines and filter for blockages, but if you didn’t, you need to start here:
- Stop your fuel flow.
- Remove the fuel line off the inlet port of your fuel pump.
- Place the line in a container placed lower than the fuel tank and restart your fuel flow.
- If you are getting fuel out of the line and into the container, you have confirmed you have flow. If not, you need to find the blockage that may be in your fuel lines or fuel filter.
Once you have confirmed fuel flow to the pump, reattach the fuel line to the inlet port. Remove the fuel line from the carburetor and place it in a container.
Check your pump is working correctly by starting your fuel flow and starting your mower. You should have a steady or pulsating flow of fuel coming out of the fuel line. If you do not, you need to replace your fuel pump.
The carburetor is a mechanical device that regulates the amount of fuel allowed to mix with air to create combustion in the cylinder.
When the carburetor is dirty, it can gum up, stick and no longer function properly. The engine in your Simplicity engine isn’t able to get the correct amount of gas it needs.
FIX: First, identify whether you need to take your carburetor apart to clean it. Confirm you are getting fuel to the carburetor. If you are not getting fuel, check for restrictions in the fuel line, fuel filter, and fuel pump.
Next, remove your air filter and spray carburetor cleaner into the air intake. Start the engine to see if it will run. If your lawn mower starts and won’t continue to run, you will need to remove your carburetor and take it apart for cleaning.
Check out this article for help with disassembling and cleaning the carburetor on your Simplicity mower.
Bad Fuel Cap
Air passes through the vent in a Simplicity fuel cap. When this vent becomes plugged, the gas tank acts like a vacuum preventing fuel from leaving the fuel tank.
You may be able to determine whether your fuel cap is clogged by starting your Simplicity mower allowing it to run with and without a cap.
If the engine runs okay without the fuel cap, but eventually shuts off or begins to run sluggish with the fuel cap in place, you may have a plugged fuel cap.
FIX: You can attempt to clean your fuel cap to unclog the vent. If this doesn’t work, purchase a new fuel cap.
It’s important to take care of your fuel system to minimize clogging and damage to your fuel components and engine. To protect your fuel system, you must start out using the right kind of gas.
Simplicity gas-powered lawn mowers require unleaded gasoline with a minimum octane rating of 87 and a maximum of 10% ethanol content.
Adding a fuel additive to reduce moisture and stabilize your fuel will help minimize clogging and running issues due to old fuel in your Simplicity.