Your mower turns over, but it just won’t start. Or, your mower does start, but it’s running sluggish. Both of these problems may occur when the engine isn’t getting a sufficient amount of fuel.

A Spartan lawn mower isn’t getting gas when the gas is old, the fuel filter is plugged, the fuel lines are clogged, the fuel pump is faulty, the carburetor is dirty or the fuel cap is bad.

Work on your fuel system in a well-ventilated area. Gas fumes are harmful. Follow all safety precautions outlined in the mowers operators manual.

Reasons Why Your Spartan Lawn Mower Is Not Getting Fuel

Bad Fuel in a Spartan Lawn Mower

Fuel can go bad and it doesn’t take long for it to begin breaking down and becoming less effective. Old fuel is often the root cause of a Spartan lawn mower not getting gas.

It’s important to always use fresh fuel. Spartan lawn mowers require an unleaded gas with a minimum octane rating of 87 and a maximum ethanol content of 10%. Avoid using gas with higher ethanol contents.

Ethanol, added to most types of gasoline, attracts moisture from the air to the fuel system. This can cause premature corrosion of the fuel system components and leave behind a varnish that can restrict the fuel supply.

It’s best to choose an ethanol-free gas or gas with low ethanol contents. Consume the gas within 30 days for best results. Use a fuel additive to keep fuel stable a little longer when you have more gas than you can consume within 30 days.

Read more about the advantages of fuel stabilizers in this article.

Solution: When you find old fuel sitting in your Spartan lawn mower, drain the fuel tank. A fuel siphon pump works great for this. Make sure you have a fuel container to collect the old fuel.

Refill your fuel tank with fresh fuel with a fuel additive mixed in. I use a product called Sea Foam Motor Treatment. Sea Foam has properties to stabilize fuel, reduce moisture and clean the fuel system.

Plugged Fuel Filter on a Spartan Lawn Mower

Check the fuel filter component for a buildup of dirt. An inline fuel filter is installed between the fuel lines to strain fuel as it comes out of the fuel tank to prevent dirt and other contaminants from passing through the filter.

A fuel filter should be replaced at least once a year. This dirt can build up in the filter causing it to become plugged so a good amount of fuel is no longer able to pass through it keeping sufficient gas from getting to the engine.

Solution: Replace a plugged fuel filter. There should be an arrow on the plastic housing of your fuel filter housing.

Make sure you install the filter correctly with the arrow pointing in the direction of the mower’s fuel flow. This means the arrow should be pointed toward the carburetor and away from the fuel tank.

Clogged Fuel Lines on a Spartan Lawn Mower

The fuel lines can become clogged with the gummy deposits that formed from running old fuel. To identify a clogged line, you will have to isolate the section of the line that is clogged and remove the clog so your Spartan mower can get fuel to the engine.

Solution: Use the fuel shut-off valve, located at the bottom of your fuel tank, to start and stop fuel flow. If your Spartan mower doesn’t use a fuel shut-off valve, use hose pinch pliers to clamp the fuel lines to stop the flow.

Once you find a section of the hose that does not allow fuel to flow, shut off your fuel and remove the fuel line. Spray carburetor cleaner into the hose and blow the line out with compressed air to remove the blockage.

If you are unable to clear the fuel line so fuel can flow freely. Replace your fuel line. It’s also a good time to replace your fuel line before it starts leaking if the line is dry and showing signs of cracking.

Bad Fuel Pump on a Spartan Lawn Mower

You will have a plastic or metal fuel pump on your Spartan mower when the fuel tank. A vacuum fuel pump is designed to build pressure using the vacuum in the crankcase. It uses this pressure to get fuel to the carburetor.

When the fuel pump has cracks, is damaged, or leaking, you must replace it with a new one. 

If you don’t notice any damage or leaking of the fuel pump, it’s time to troubleshoot the fuel pump to ensure it is working correctly.

Solution: Confirm the fuel pump is functioning properly by, first, checking to make sure you are receiving fuel flow to the inlet port on the pump. Remove the fuel line from the carburetor and place it in a container. Next, start your fuel flow and start your mower.

You should see a steady or pulsating stream of fuel flowing out of the fuel line signifying your fuel pump is working correctly. Replace a bad fuel pump that is damaged or is not supply enough fuel from the pump.

Dirty Carburetor on a Spartan Lawn Mower

A Spartan mower uses a carburetor to regulate the fuel that is mixed with air to form a combustion in the engine cylinder. You will find your carburetor mounted to the top or side of the engine block. It is usually below or behind your air filter.

When the carburetor is dirty, the components of your carburetor, including the fuel jet, can become clogged preventing the Spartan mower from getting fuel to the cylinder.

First, to help identify a carburetor problem, make sure you are getting fuel to the carburetor. Next, remove your air filter for the air filter housing and spray a little carburetor cleaner into the air intake.

Start your engine to see if it will run. If the mower starts, runs, and then shuts off, you will need to remove your carburetor and take it apart for cleaning.

This is a test to make sure your mower will start using the carburetor cleaner. If it doesn’t, you may have a problem other than a fuel issue.

Solution: Clean the carburetor. This is something most homeowners can do if they are a little mechanical and don’t mind working with small parts. If that’s not you, your local lawn mower repair shop can do this for you.

For instructions on cleaning the lawn mower carburetor on your Spartan mower, read this article.

Bad Fuel Cap on a Spartan Lawn Mower

The fuel tank needs to vent through the fuel cap so it doesn’t act like a vacuum restricting fuel from leaving the fuel tank. When the fuel cap vent is clogged it prevents air from passing through the cap.

To check if your fuel cap is the problem, remove the cap, start and let your mower run. If it runs fine, install the fuel cap while continuing to allow your mower to run for a while.

If it eventually shuts down with the cap installed, but starts and runs again as soon as you remove the cap, you may have a problem with a clogged fuel cap.

Solution: You can attempt to clean your cap to remove the cap. This doesn’t always work and you will have to purchase a new fuel cap.