Snowblower Stalls When Auger Engaged

It's frustrating using kit that's just not up to the job. Snowblowers have it tough, but do they really? They only work a few months of the year, not a bad gig and that is the root cause of your problem.

In this post you'll learn why your snowblower stalls when the auger is applied. You'll learn how you can fix it today and how to prevent this happening again.

The root cause is as you now know, most likely a dirty carburetor. Tiny fuel passages inside your carburetor become clogged and restricts gas flow.

When the auger is engaged, the engine demands more fuel, when the carburetor can't supply it, the engine simply stalls.

This condition is known as fuel starvation.

Although a fueling issue is the most likely cause, it's not the only possible cause.

A fault with the auger brake assembly may also cause the engine to stall when the auger is engaged. It is however the less likely cause and so we'll look at it towards the end of this post.

First we'll look at the fueling system.

For an engine to run without stalling it needs a mix of air (oxygen) to gas ration of 14.7:1

It's known as the AFR (Air Fuel Ratio). It means for every 14.7 parts air the engine receives, it must also receive 1 part gas.

If either of these measurements are off, the engine protests by not running at all or poorly.

If the engine doesn't get enough gas in the mix, it's said to be running lean.

If on the other hand, the engine isn't getting enough oxygen, it's said to be running rich.

In our case, we suspect we a have fuel starvation issue, (lean) evidenced by the stalling engine precisely when more gas is needed (auger engaged).

It should be noted that a lean condition and fuel starvation aren't quite the same thing. A lean condition as you know means there's isn't enough gas in the mix.

The most common cause of a lean condition is a dirty carburetor, but there are many other root causes of a lean condition.

The good life may well be the root cause of your snowblowers stalling issue. When snowblowers retire at the end of the season, the gas in the fuel system starts to degrade.

Some owners drain the gas tank, however it's the gas in the carburetor bowl that's the problem. The ethanol fuel blend we all use today begins to degrade after just a month.

And degraded gas is the most likely cause of fuel starvation.

Diagnosis is pretty simple, remove the carburetor bowl and check the contents. Finding a gungy deposit, corrosion or dirt means we found our problem.

In some cases cleaning the carburetor bowl and fuel jet will solve the issue. It's worth a try, as cleaning the bowl and jet is a ton less labor than removing the carburetor to clean.

After refitting the bowl, check for leaks, older carb bowl seals and bowl fastener gaskets often leak after removal. If they do leak, replace the gaskets.

Cleaning the carburetor thoroughly means removing it. It is possible to spray carb cleaner into he carb but it's like shooting in the dark.

Removal, stripping, cleaning, rebuilding and refitting is the best solution. However, as said it is worth cleaning just the bowl and bowl fastener (jet type) before embarking on a carb teardown.

Small engines are easy to work on, for most task just basic tools are needed. That's true for this task. If you need tools, check out the "Snowblower maintenance tools page". 

 You'll find all these tools & products here on the "Snowblower maintenance tools page". 

To nail this task you'll need carb cleaner or better an Ultrasonic bath. 

To prevent this problem in the future we have two options. One: We can drain all the gas from the machine including the gas bowl and fuel lines, or Two: We can add a gas stabilizer that will keep the gas fresh and protect the fuel system from gumming.

The gas stabilizer is mess free and a lot less work. Gas stabilizer is a chemical additive we add to the gas tank to keep the ethanol from going stale or eroding the plastic and rubber components of the fuel system.

You can check out the stabilizer I use here on the "Snowblower maintenance tools page".

Told you it was easy!

The auger is fitted with a brake to stop it quickly when the handle bar auger lever is released.  

The system is simple, a spring loaded arm with brake block attached is pushed against the auger pulley, slowing it down and stopping it when the auger lever is released.

A brake is activated by way of cable from the auger lever.  

As you can imagine if the auger brake isn't releasing then the engine would naturally stall. This isn't a common problem, but should be eliminated as a possible cause. 

The system is simple, a spring loaded arm with brake block attached is pushed against the auger pulley, slowing it down and stopping it when the auger lever is released.

A brake is activated by way of cable from the auger lever.