You smell strong fuel fumes when you enter the garage. You have identified the smell is coming from your Snapper mower, but you can’t find any signs of gas leaking. It can be difficult to identify a leak after your mower has been sitting a while because fuel evaporates. You aren’t left with any wet areas that easily identify your leak.
A Snapper lawn mower may be leaking gas from a failed gasket or stuck parts on the carburetor. The effects of running old gas through the mower can cause components to degrade and cause leaking. Fuel components can also begin to leak when they age and become dry and brittle.
I have put together a list of items below to help you isolate the fuel leak on your Snapper mower.
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Follow all safety instructions provided in your equipment operator’s manual prior to diagnosing, repairing or operating. Consult a professional if you don’t have the skills, knowledge or are not in the condition to perform the repair safely.
Reasons Your Snapper Mower is Leaking Gas
- Carburetor is dirty
- Fuel filter is old or cracked
- Fuel pump is old or cracked
- Gas tank is rusted or has a failed seam
- Fuel shut-off valve not sealing
- Fuel lines are dry or cracked
- Primer bulb is cracked
- Gas cap has a bad seal
Snapper Carburetor is Leaking Gas
A small amount of fuel is stored in your carburetor. Additives left behind by old fuel can cause carburetor problems due to the gumming and crusty buildup. Your Snapper lawn mower uses a carburetor that contains several small parts that can freeze up and no longer work correctly. You will also find a gasket around the bowl that is prone to drying out and leaking.
Gasket failure in the carburetor bowl on you Snapper Mower
You will find a gasket located between the carburetor bowl and the carburetor. The bowl is the piece located at the bottom of your carburetor. The gasket, which looks like a rubber band, can become dry and brittle due to its location on your Snapper lawn mower.
The carburetor is mounted next to the engine. The gasket heats up when your engine is running and cools off when it is not. The constant change in temperature puts stress on the gasket causing it to lose its sealing capabilities. When this happens, your Snapper carburetor will begin leaking out of the bowl.
Fix: A bad gasket on your Snapper is an easy repair. First, shut off the fuel supply using your fuel shut-off valve located underneath your fuel tank. If your mower doesn’t have a shut-off valve, use a clamp on your fuel line to stop fuel flow. Second, remove the screw at the bottom of the bowl.
Clean around your bowl so you don’t allow any debris or other contaminates into the carburetor when removing the bowl. Have a rag ready to collect gas in the bowl and remove the bowl. Take the old gasket off the bowl and put a new gasket in place. Lastly, Reinstall the bowl and replace the screw to hold it together.
Stuck float in your Snapper mower’s carburetor
Another place on your carburetor you may find leaking is near the air intake port. When you find a leak in this area, it may indicate you have a stuck carburetor float. The float is the piece on your carburetor that regulates how much gas is allowed into the bowl. It starts and stops flow into the bowl.
When the float gets stuck, gas continues to run into the bowl and will overflow allowing excess gasoline to run out of the carburetor.
Fix: The carburetor will have to be disassembled to find the reason why your float need is stuck. You may be able to clean the carburetor parts to get your float working or you may have to rebuild it. Find the steps to clean your carburetor in this article.
Stuck float needle on your Snapper Mower
The float needle works with the float to keep gas flowing in to the bowl. The needle can become stuck and will need to be replaced.
Fix: You can try to “unstick” your float needle by tapping the side of your carburetor gently with a small rubber mallet or the handle end of your hammer. This is only a temporary fix that may only work a time or two. You will have to take your carburetor apart and replace the needle.
Snapper Fuel Filter is Cracked or Deteriorating Causing a Leak
The fuel filter can begin leaking when it has been damaged. It can also degrade over time causing the plastic to become weak and soften causing the filter to leak at the seams.
Fix: Remove your fuel filter and replace with a new filter. Be careful when removing the ends of the filter from the fuel line. The plastic can get soft and break off inside the fuel hose. Your fuel filter must be installed with the arrow on the side of the filter pointed in the direction of the fuel flow.
Bad Snapper Fuel Pump Can Begin Leaking Gas
Your Snapper mower will use a fuel pump when the carburetor sits higher than the fuel tank. Just like the plastic on your fuel filter can degrade, the components of your fuel pump can deteriorate and degrade causing it to leak.
Fix: Replace your fuel pump when you find the pump is leaking gas. Again, be careful not to break off any soft plastic from the ports off the fuel pump.
Rusted or Failed Seams on Your Snapper Fuel Tank Will Begin Leaking Gas
Gas tanks on Snapper mowers today are made of a high-density polyethylene gas tank. Check the seams on your tank for a fuel leak. Replace with a new fuel tank when you find a leak.
Older lawn mowers use a metal fuel tank. These types of tanks can develop rust and holes where fuel will begin leaking. Most likely, you will have a hard time trying to find a metal tank on these older mowers. You can try to use a petroleum resistant epoxy like TankWeld by J-B Weld to patch the hole.
Snapper Fuel Shut-Off Valve is Prone to Leaking Gas
Your Snapper lawn mower may use a fuel-shut off valve. If it does, you will find it at the bottom of your fuel tank. It can be made of plastic or metal. This part is prone to leaking.
Fix: Replace your shut-off valve if you find it leaking gas
Old Snapper Fuel Lines Can Become Dry and Leak
With age, the fuel lines on your Snapper can become dry and cracked allowing fuel to leak from the lines. The lines can also become punctured by the clamps holding on the hose allowing gas to seep from the lines.
Fix: Any cracked Snapper fuel lines need to be replaced. This may also be a good time to replace the type of fuel clamps if your mower uses a pinch-style clamp. I like using a worm gear clamp because they are less likely to pinch your lines and cause leaking.
Cracked Primer Bulb Can Begin to Leak Fuel
Your Snapper mower may have a primer bulb to prime the carburetor for starting the mower. Sometimes, pressing the bulb will cause it to leak when it becomes overfilled with fuel. It may also leak where the bulb meets the fuel line or from becoming dry and brittle. A primer bulb is relatively easy to replace if you find any gas leaking.
Bad Snapper Gas Cap Seal Can Cause Leaking
If you have gone through the list and still can’t find your fuel leak, you need to check the gas cap seal. You may have not seen a wet spot form around your fuel tank cap because you weren’t looking for it when you finished mowing.
Now you smell gas and any wet signs have evaporated. Check the seal in the cap by rocking your mower back and forth to splash gas around the tank cap area. Watch for wet areas developing around the cap for signs your cap seal is bad.
Fix: Replace your Snapper gas cap if you see wet fuel spots forming around your cap.
Purchasing Parts for Your Snapper Lawn Mower
Make sure you have the right information on hand so you order the correct parts for your lawn mower. For parts on your Snapper mower, collect the model and serial number. For engine parts, you must get the model and spec number off the engine itself. Sometimes you will only find a QR code that you need to scan to get this information. You will need the engine information when ordering parts for the engine including the carburetor and fuel pump.
Use the Correct Gas in your Snapper Mower to Minimize Fuel System & Engine Problems
Using a fuel with a reduced content of ethanol is beneficial for your Snapper mower. Ethanol isn’t good for your Snapper engine and can cause damage to your fuel system and engine. Make sure the fuel you run through your mower has no more than a 10 percent ethanol content.
I recommended adding a fuel additive to stabilize your fuel since it can break down as soon as 30 days after purchase. Read more about the correct gasoline to use in your Snapper mower here.