You may smell gas coming from your mower, but you don’t see a puddle of gas under the mower and you can’t find any evidence of a fuel leak. It can be hard to find the cause of a leak especially when the wet spot may have evaporated.
A Spartan lawn mower may begin leaking gas from a stuck carburetor float; a bad carburetor gasket; old fuel lines; a degraded fuel filter, fuel pump, or fuel tank; a bad fuel shut-off valve; or a bad seal in the fuel cap.
Always work on your mower in a well-ventilated area. Gas fumes are harmful. Follow all additional safety precautions outlined in your Spartan operators 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.
Troubleshoot: Spartan Lawn Mower Leaking Gas
- Check the carburetor leaking around the bowl or near the air intake
- Check fuel lines and clamps
- Check fuel filter
- Check fuel pump
- Check fuel shut-off valve
- Check fuel tank seams
- Check fuel cap seal
This is Where Your Spartan Lawn Mower is Leaking Gas
Lawn Mower Carburetor
A carburetor is a common place for your Spartan mower to start leaking. This is a component where a little gas is stored after it leaves the fuel tank.
In time, the carburetor parts can stick from the varnish left behind by old fuel or the carburetor gasket can fail to cause the mower to leak.
Carburetor Bowl Gasket
You will find the gasket located between the carburetor and the bowl placed at the bottom of the carburetor. This gasket looks a lot like a rubber band.
The function of the gasket is to form a seal between the carburetor and the carburetor bowl. This gasket is known to dry out and lose its sealing capabilities because of its exposure to extreme temperature changes.
Because of its location near the engine, the gasket heats up when the mower is running and cools down when it is not. This stress on the gasket can cause It to fail to result in fuel leaking from the carburetor. The gasket must be replaced when the gasket fails.
Replace the carburetor bowl gasket on your Spartan mower:
- Shut off the fuel supply using the fuel shut-off valve or crimp the fuel line to stop the flow.
- Wipe off the dirt around the carburetor so foreign material does not get into the carburetor.
- Remove the screw at the bottom of the carburetor and remove the bowl. Have a rag available to catch any fuel that remains in the bowl.
- Remove the old gasket.
- Replace the new gasket. Be careful not to get any carburetor cleaner or other material on the gasket.
- Reinstall the bowl and tighten the screw to hold the bowl and carburetor together.
- Wipe down the carburetor.
If the gasket around the bowl is not the place that is leaking on your carburetor or you replaced the gasket and continue to have a leak, check the float on your carburetor.
Stuck Float
Look for a leak near the air intake. A leak in this area may signify you have a stuck float. The float is the part in the carburetor that kind of acts like a gatekeeper. It determines when to allow fuel to flow into the carburetor and when to stop the flow.
Deposits left behind by old fuel can cause your float to stick. When this happens, the float can no longer regulate fuel flow into the carburetor. Fuel can continue to flow into the carburetor and overflow with fuel running out of the carburetor.
To determine the actual reason why your float is sticking, the carburetor will need to be taken apart. You may have to clean the carburetor and float or replace the float. You can find steps to clean your Spartan carburetor here.
Stuck Float Needle
While checking the float, you may find the float needle needs to be replaced. The float needle works with the float to keep gas flowing into the bowl. If the needle sticks, you must replace it.
Sure, tapping the side of your carburetor a time or two with a rubber mallet may unstick your needle, but this is a temporary fix and you will have to replace it.
To order parts for your carburetor, you must have the engine model and spec to ensure you get the right parts. Again, you need the information from the engine housing and not the actual mower model and serial number.
Cracked or Soft Fuel Filter
Fuel can degrade and soften the fuel filter when it hasn’t been changed regularly. The plastic can become weak and begin leaking at the seams. It’s good practice to replace the fuel filter regularly to minimize the chance of the filter becoming plugged or leaking.
Replace a fuel filter that has become soft or is cracked and leaking. Be careful to not break off the ends of the filter while removing it from the fuel lines as they may be soft.
Install the new filter on your Spartan lawn mower with the arrow on the side of the filter facing in the direction of the fuel flow.
Bad Fuel Pump
Old fuel sitting in your fuel pump can degrade the plastic housing causing the plastic to become soft and develop leaks at the seams. A vacuum fuel pump needs to be replaced when you notice it is leaking.
Failed Seams on Your Fuel Tank
Your Spartan lawn mower uses high-density polyethylene to form the tank. The seams on the tank can fail over time causing a fuel leak. When this happens, you should replace your fuel tank.
Fuel Shut-Off Valve
Fuel shut-off valves are prone to leaking. It must be replaced if you find it is the cause of your fuel leak.
Old Fuel Lines
Fuel lines will become dry with age. That can result in cracking and leaking. The fuel lines may also have been punctured by the clamps used to secure the fuel line to the fuel components. These clamps can become loose or puncture the line causing a leak.
Replace any dry or cracked fuel lines found on your Spartan mower. This is also a good time to convert your clamps to a worm gear clamp if your mower came with pinch-style clamps.
The worm gear clamps are less likely to cause leaking because they don’t actually pinch your lines.
Bad Fuel Cap Seal
The seal in your gas cap may have failed. When running your mower, gas sloshes around the tank and can leak around the cap when it isn’t sealing correctly.
If you smell a fuel leak and have checked all the items above, it’s time to check the fuel cap seal. You may have missed the wet spot that formed around the fuel cap because fuel will evaporate leaving no trace of a wet spot.
To check for a leak with your fuel cap installed, gently rock your mower back and forth to splash fuel up to the cap area. Watch for a wet spot to form an indication you need to replace your fuel cap.
Still Having Problems With Your Spartan Zero Turn Mower?
It would be nice to own a mower that will never give you problems. However, they don’t exist. When you own a mower long enough, you are bound to run into problems.
The most common of them are problems with starting, smoking, dying, vibrating, and cutting.
I put together a handy guide to help you quickly identify items that can cause a problem with your mower. You can find this guide at Common Spartan Lawn Mower Problems & Solutions.
If you are unsure how to safely perform diagnostics and repairs, it’s best to have a professional complete the repairs.
This will help you avoid personal injury or additional damage to the mower. Your local Spartan lawn mower dealership or lawn mower repair shop will be able to help you solve your problem.