Lawn Mower Not Getting Gas to Carb? Fixes that Work

It’s frustrating to work with a lawn mower that is not getting gas to carburetor. It may have a hard start, stalls when running or fail to start completely. So, why is a lawn mower not getting gas to carburetor?

Several factors can hamper a free flow of fuel into the carburetor, they include: Empty fuel tank, clogged fuel filters and fuel lines, old fuel, plugged gas cap, and a stuck float or float needle. In most cases, using old fuels may corrode the carburetor fuel flow system leaving behind thick and sticky substances that clog the filters and fuel lines.

Why is my Lawn Mower Not Getting Gas to the Carburetor?

Lawn mower not getting gas to carburetor may result from:

1. Empty Fuel Tank

Do you have enough fuel in the tank? The first thing to do is to check the fuel tank to ensure it is having sufficient gas. The fuel tank needs to have at least some fuel to power the motor. Refill the tank and try to restart your lawn mower. If the lawn mower start but stop when accelerating, it may not be getting sufficient fuel in the carburetor.

2. Clogged Fuel Filters

Lawn mowers are fitted with fuel filters on the fuel lines to strain any dirt, sediments and other contaminants present in the fuel from entering the fuel system. Using dirty fuels for a long period of time can clog the fuel filters. Fuel cannot flow through clogged fuel filters to reach the carburetor.

3. Plugged Fuel Lines

Thick and sticky deposits left behind from using old fuel can clog the fuel lines and prevent free flow of fuel to the carburetor. Check the fuel lines to find the clog, you have to check all the sections and unclog the blocked parts.

Run a carburetor cleaner through the pipes to loosen and remove clogs along the line. Control the fuel flow from the tank using a shut-off valve located at the bottom of the mower’s gas tank when cleaning the fuel flow lines.

4. Old Fuel in the Tank

Running your lawn mower on old fuel can cause restrictions and prevent the gas from getting into carburetor. When the fuel is stored for a long period of time, some ingredients evaporates leaving behind thick and sticky substances that end up clogging fuel filter, gas lines and carburetor fuel system.

Most fuel contains ethanol to make them environmentally friendly. However, ethanol naturally attracts moisture from the air to form a sticky substance that may clog the fuel system. When intending to use fuel for a long period of time. Be sure to use a stabilizer, it helps to keep the fuel fresh for long.

5. Stuck Float or Float Needle

Fuel cannot get in to the carburetor if the float or float needle is stuck. Float needle plays an important role of regulating the amount of fuel flowing into the bowl. A stuck float needle won’t allow fuel to flow into the bowl. This problem is temporarily fixed by tapping on the carburetor gently with a rubber mallet. Clean the carburetor and replace the float or float needle if the problem persist.

6. Clogged Gas Cap

The top of a gas cap has a tiny hole that allow air into the fuel tank so as the gas can flow into the carburetor. When this vent is plugged it create a vacuum that prevent the fuel from flowing into the carburetor. Remove dirt and other debris from the vent to create necessary pressure required to take gas into the carburetor.

To diagnose this problem, try to run a lawn mower without fuel cap. If the engine runs okay without the fuel cap and eventually stops with the cap, then the problem is with the cap

Signs that a Lawn Mower is Not Getting Gas to Carb

There are several telltale signs that your mower is not getting fuel to the carb, they include:

Lawn Mower Experiencing a Hard Start

If your lawnmower is experiencing a hard start, it’s usually a result of stuck float needle. A hard start happens when the carburetor is not receiving fuel flow as required. The float and float needle helps to regulate the amount of fuel in the bowl. To fix this problem, you have to clean the carburetor and replace the float needle.

Lawn Mower Won’t Start Completely

If your lawn mower won’t start completely, there is usually a problem with the flow of fuel to the carburetor. It usually results from dirt and debris collecting and blocking the fuel transmission system and other components such as fuel filters, fuel pipes, stuck needle, carburetor bowl and the gas cap vent.

Check the filters, gas pipes, carburetor fuel system and gas cap to ensure they are not clogged by dirty or thick and sticky substances from old fuel. Wash the carburetor and fuel pipes with a carburetor cleaner to fix this problem. Replace fuel filters and float needle to get your lawn mower working again.

Lawn Mower Starts then Stalls when Running

If the fuel tank is filled up with fresh gas but your lawn mower starts then stalls after a few second when accelerating, there is high chances that the vent on the fuel cap is clogged. It creates a vacuum that cut pressure that is needed to push the fuel into carburetor.

Check the gas cap vent to remove dust and other debris that may be plugged in. If it doesn’t work, you may be require replace it with a new gas cap.

No Fuel Odor

If your lawn mower can’t start and at the same time you can’t sense any smell of fuel coming out of the motor, it simply means that the mower run out of the gas. Check the fuel tank to see if it having fuel, refill with fresh gasoline if the tank is empty.

Use a check stick to determine the level of fuel in the gas tank. The check stick has two marks, the low and high level mark. If the fuel is below the low level mark, you simply need to refill your fuel tank. With an empty fuel tank, the carburetor won’t get fuel.

How to Fix a Lawn Mower that is Not Getting Gas to Carb

Lawn mowers problems such as not getting fuel to the carburetor can happen in the middle of mowing. Here are some simple fixes you can use and get back to work:

1. Fill up the Fuel Tank

Have you tried to check the fuel tank? An empty gas tank can also be the reason why fuel is not getting to the carburetor. If the fuel tank is empty refill it with fresh fuel and try to run the engine again. It should be able to run smoothly.

2. Use Fresh Fuel

Using old gas tends to clog up the carburetor fuel system which prevents free flow of gasoline. Therefore, you should always use fresh fuel that is not older than a month. If intending to use the same fuel for over a month, use stabilizers to keep the gas fresh. It prevents the fuel from degrading.

3. Replace Clogged Fuel Filters

If your lawn mower is not getting gas to the carburetor, the most likely cause is a clogged fuel filter. This usually happens when using dirty oil or when you leave fuel in the tank for a long period of time. Draining the fuel tank, replacing the filter and refilling with clean fresh fuel should be able to fix this problem.

4. Clean the Carburetor

Dismantle the carburetor and clean it thoroughly using a carburetor cleaner. Be sure to remove dirt and other debris that may be clogging in the fuel system. Check out the fuel bowl and fuel filters in the carburetor to ensure they are well cleaned. A clean carburetor will get your lawn mower running again.

5. Replace Carburetor Float or Float Needle

If your lawn mower is experiencing a hard start, the problem is usually a float needle. Take your carburetor apart to determine the exact cause of the failure. Clean the carburetor and replace the float needle when necessary. Rebuilt your carburetor and restart the engine.

6. Unclog the Gas Cap

Tiny opening on the fuel cap creates a vent that allow air into the fuel tank to pressure the gas into the carburetor. When it is clogged, it creates a vacuum that prevent the fuel from getting into the carburetor. Remove dirt and other debris that may be clogging this vent.

7. Unclog the Fuel Pipes

Remove the fuel line from your lawn mower, check to find a section of the line to find the clog. Run through a carburetor cleaner to loosen the clog. Blow out the line with pressurized air to flush out the debris. Repeat this procedure to ensure the whole line is clean and open.

Final Thought

Owning a lawn mower comes along with some challenges and frustrations. Some of the problems like fuel not getting into the carburetor can happen anytime even when in the middle of mowing. Knowing the cause and how to fix can help to get the engine running smoothly again. Clean the carburetor, unclog blocked fuel pipes and clean the gas cap vent to ensure the mower’s engine is running efficiently.

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