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Mower Fuel Tap – Location, function, and operation

By: Author John Cunningham. Published: 2018/12/08 at 3:20 pm

First off, fuel taps are not fitted to all mowers, so you might be looking for something you don’t have. If your mower is a Honda or has a Honda engine fitted, it will certainly have a fuel tap.

So, what is a mower fuel tap? A mower fuel tap is a valve; its function is to allow the operator to control the fuel supply to the carburetor by turning a tap on or off. It’s commonly located in the gas line between the gas tank and the carburetor.

They’re usually plastic, but older mowers may have a metal tap fitted. A fuel tap is also known as a fuel valve, shut-off valve, or gas tap. It’s sometimes marked with an arrow to show gas flow direction. Some larger mowers will have a fuel valve solenoid that automatically shuts off fuel when the engine is shut off. 

This post should have you covered on fuel tap location and use; if, however, you need video help, check out “Mower gas tap video.” It walks you through locating and using your mower gas tap. The video library has a ton of other useful mower repair videos, too. 

Where Is The Gas Tap?

First, I should point out that not all mowers will have one fitted. Fuel valves are sometimes incorporated into the carburetor, but mostly, they are somewhere along the fuel line. To find it, follow the fuel line from the bottom of the fuel tank all the way to the carburetor. A fuel tap will be in an accessible area along this fuel line (If fitted).

Where? – It’s fitted between the gas tank and the carburetor, somewhere along the rubber fuel line. The fuel valve isn’t fitted to all mowers.

Valve – The gas valve seen here is made from plastic, but some are made from metal.

Gas tap

Walk-behind mower tap location

How To Use Gas Tap?

Gas “Off” – The gas tap is seen here in the “Off” position. Some valves will have an on/off symbol.

Gas “On” – Tap seen here in the “On” position.

What Is A Fuel Solenoid?

A fuel shut-off solenoid is an electrical valve, and it’s fitted to some walk-behind mowers and most modern Tractors, Ride-on, and Zero turns. If fitted, it will be fitted in the fuel bowl at the base of the carburetor. You’ll easily identify it, as it will have an electrical connector attached.

What’s it do? – The fuel solenoid is controlled with the ignition key. When energized, its valve retracts and allows gas to flow from the carb bowl to the engine. When the mower key is turned off, the spring-loaded solenoid resets to its default position (see pic) and blocks the gas flow.

Where? – Fuel shut-off solenoid lives at the bottom of the carburetor and has an electrical connector.

When To Use The Gas Tap

Gas taps are really useful, and in the workshop, I make great use of them during routine maintenance and tune-ups. But they have some other important uses too.


Turning the valve off before starting any maintenance jobs is just good practice and will prevent fuel spills. Cleaning, removing carburetors, or just taking a fuel sample is so much easier with the valve. In the workshop, I use them all the time, especially when troubleshooting carburetor issues. When no fuel tap is fitted, I use a clamp to cut the fuel supply.


Inspecting the drive axle and blade or cleaning the deck will require turning the mower over. Turning the valve off before turning the mower over will prevent fuel from flooding the cylinder. 

When fuel floods the cylinder, it can cause a few different problems:

  • Hydro-locking the engine – cylinder fills with gas, which stops the engine from cranking
  • Fuel can saturate the plug, causing a no-start
  • Fuel can spill onto the air filter preventing proper airflow
  • Fuel can seep into the crankcase, causing a high oil level and a smoky engine

Draining Gas

We’ve all been there – put bad gas, diesel, and paint thinner ….. into the gas tank. The fuel valve makes draining the fuel tank hassle-free and mess-free. Remove the gas line from the carburetor, place it into a container, and turn on the valve. Easy!

Winter Storage

The valve should be turned off when the mower isn’t in use; this takes the load off the needle valve. Using a fuel stabilizer in the gas tank will leave you set for winter and make easy work of recommissioning in the spring. 
Why not go all the way and clean the deck and coat it with WD40 or Teflon Non-Stick Lubricant – it protects and repels grass, moisture, and debris. When you need to inspect or clean your mower, if possible, lift it from the front (Handlebars to the ground). If this isn’t possible, then always turn the carburetor side up. 
Check out the complete guide “How to winterize your mower.”


Transporting your mower by trailer can cause the carburetor to leak gas into the engine. When the gas fills the cylinder, it prevents the piston from moving, a condition known as hydro-locking. This happens because bumps in the road move the float needle out of its seat. This allows gas to fill the cylinder, wetting the plug and causing a no-start.

Newer model ride-on engines have a fuel solenoid fitted, which makes this condition less likely. Some models have a fuel pump fitted; these mowers are less likely to suffer from hydro-locking.

The fuel tap is especially useful when transporting your mower over rough ground or by car and trailer from one location to another.

The constant bumping around can cause fuel to flood the engine. This usually floods the spark plug and results in a no-start.

Can I Fit a Valve?

Yes, it’s the easiest job ever. Order a fuel valve online; they’re a universal fit. Two types are common – straight or elbow and both are available in metal or plastic. However, they are available in different diameters depending on your gas line size; 1/4″ is more common. Choose the one that suits you best, usually the plastic straight flow.

1 Tool – Tools needed are gloves, rags, knives or sharp pliers, cable ties, or fuel line clamps.

2 Cut – Go ahead and cut your fuel line anywhere you have good access to work. If your fuel line is bad, now’s the time to take care of it.

3 Push On – Push the valve onto the fuel tank side of the cut fuel line first, and then put the valve in the off position.

4 Zip – Finally, fit your hose clamps or cable ties. I like cable ties – they’re fast but only single use. Now turn the fuel on and check for leaks. Nice work!

Related Question

Are mower fuel taps universal? Mower fuel taps are universal. However, there are different diameter taps to suit different applications. Most mowers will use a 1/4″ ID fuel line, and the universal fuel tap is a push-on fit.