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Your Snowblower Won’t Stay Running (Check These 8 Items!)

It’s frustrating when you’re out in the cold trying to remove snow from the driveway before the next snowstorm gets here when the snowblower stops running. Getting it up and running soon is essential or you’ll have to result to using a manual snow shovel.

A snowblower won’t stay running when the gas is old, the fuel line is clogged, the carburetor is dirty, the choke setting is incorrect, the spark plug is dirty, the ignition coil is faulty, the fuel cap is bad or there is too much oil in the crankcase.

Remove the spark plug wire before performing repairs. Follow all other safety procedures outlined in the operator’s manual.

Snowblower won't stay running

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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.

Reasons Your Snowblower Won’t Stay Running

Bad or Old Gas

Gas that has been sitting in the fuel system for a long period can often be the reason the snowblower begins to run sluggishly and stops running. This is because gas begins to break down as soon as 30 days after purchasing it.

Ethanol-based gasoline attracts moisture from the air. Over time it causes corrosion in the fuel system and leaves behind gummy deposits that restrict fuel flow to the engine.

Read more about ethanol and the right gas to use in “This is the Type of Gas Snowblower Use“.

SOLUTION: If you find old fuel, drain the fuel tank using a fuel siphon pump. Mix a fuel additive like Sea Foam Motor Treatment to stabilize the gas, reduce moisture and clean the fuel system.

Add this fuel and Sea Foam mixture to the fuel tank. Start the snowblower and allow it to run so the mixture works its way through the fuel system. The snowblower should start to run better.

If it doesn’t, continue through this list to check for other items that can cause your running problem.

Clogged Fuel Line

Look for a clogged fuel line. Old fuel can leave behind deposits in the line that restricts fuel flow.

To check the fuel flow in a fuel line, stop the fuel flow using the fuel shut-off valve or fuel hose pinch-off pliers to crimp the line. Next, remove the hose end from the section of the fuel line furthest from the fuel tank.

Place the hose end into a container placed lower than the fuel tank. (Fuel will only run downhill without the help of a fuel pump). Turn the fuel supply back on and watch the flow coming out of the line into the container.

Shut the fuel flow off and reattach the fuel line if you are getting good flow. If you are not getting good flow, remove the section of the fuel line from the snowblower.

SOLUTION: Spray carburetor cleaner into the line to loosen the clog. Follow this with compressed air to remove the clog. Repeat as necessary until the clog no longer remains in the fuel line.

Reinstall the clog-free fuel line or replace it with a new one if you can’t remove the clog. If the fuel line appears dry and cracked, install a new line to avoid developing fuel leaks from this area in the near future.

Dirty Carburetor

A carburetor is used on a snowblower to regulate the amount of fuel that is mixed with air to form combustion in the engine cylinder. When it isn’t able to function properly, the engine may stop running due to a lack of fuel.

The carburetor is one item that is known to get dirty and fail to work due to old gas running through the snowblower. This old gas leaves behind a varnish that can clog the fuel jet, make the float stick, and gum the internal parts.

When this happens to your carburetor, it must be removed from the snowblower and cleaned. You will have to rebuild it or replace it if you find any damaged parts or the carburetor is in bad condition so cleaning does not help.

SOLUTION: To better determine if you are experiencing a running problem due to a dirty carburetor, perform these quick steps:

  • Confirm you are getting good fuel flow to the carburetor.
  • Spray carburetor cleaner into the air intake and allow the snowblower to run. If it runs strong while it burns the carburetor cleaner, but then begins to run sluggish and possibly shut off once the cleaner is burned, chances are your carburetor is dirty.
  • Proceed with disassembling the carburetor and cleaning it.

Choke Set in the Wrong Position

The choke is required to assist with starting a cold engine. The choke must be placed in the closed position so it restricts airflow and allows more gas into the cylinder to start.

Once the engine warms, the choke needs to be adjusted to the open position allowing more air to flow so the engine gets the correct gas-to-air mixture to continue to run.

SOLUTION: If the choke isn’t adjusted correctly, the engine will begin to run sluggishly and won’t stay running because the amount of airflow is too low.

Make sure you are following the correct start-up procedures for your snowblower. Consult the operator’s manual if you are unsure.

Dirty Spark Plug

A fouled spark plug can keep a snowblower from running. When it becomes dirty and coated with carbon or oil, the plug may fail to spark causing intermittent running problems.

SOLUTION: Remove the spark plug and check its condition. If it is very dark in color or has broken porcelain or burnt electrode, the spark plug must be replaced with a new one.

If the tip is lightly dirty and otherwise in good condition, you can proceed with using it, but you need to clean it with a wire brush to remove any carbon and dirt buildup.

Check the gap of the spark plug to make sure it is gapped to the engine manufacturer’s specification. You can find this information in your operator’s manual.

A spark plug that isn’t gapped correctly or one where the spark plug wire isn’t securely attached can also result in running problems with your snowblower.

Once you confirm you are using a good spark plug or you replaced it with a new one, proceed with checking your ignition coil if you are still experiencing spark issues.

Bad Ignition Coil

Before checking for an ignition coil problem, confirm your spark plug is in good condition, gapped correctly, and has a securely attached wire.

The windings on the ignition coil can separate and short out when the snowblower gets hot.

This will result in the spark plug not being able to create a spark because it is unable to get the voltage it needs.

SOLUTION: Check for a break in the continuity using an ohmmeter. Replace a faulty ignition coil.

Too Much Oil

When there is too much engine oil in the crankcase your engine may smoke, run terribly, and eventually shut down. Too much engine oil can get up to your spark plug, into your cylinder, and hydro lock your engine.  

SOLUTION: If you are running a snowblower with a 4-cycle engine, check the crankcase oil level to make sure the oil level isn’t too high. If it is, remove a little oil until it is at the full level recommended by the manufacturer.

On a snowblower with a 2-cycle engine, the gas-to-oil ratio must be as required by the manufacturer. Running more oil in the gas-to-oil mix than required must be corrected. Drain the fuel and fill it with the correct gas-to-oil mix.

Bad Fuel Cap

The gas cap on a snowblower includes a vent to allow air to pass through the cap. This allows the air pressure inside the tank to be equal to the pressure outside the tank.

When the vent in the cap becomes plugged the fuel tank will form a vacuum. This vacuum will prevent gas from flowing out of the tank through the fuel lines.

This will cause the engine to shut down because of a lack of gas to the engine.

Once the snowblower has stopped running and won’t start, remove the fuel cap and attempt to start the engine. If it starts and runs fine, you may have a problem with the fuel cap vent.

For added confirmation, reinstall the cap back on the fuel tank while allowing your engine to continue to run to see if the snowblower shuts off after running for a while.

If it does and will not start, check to see if loosening the fuel cap will allow it to start.

SOLUTION: Replace the bad snowblower fuel cap with a new one.