If your snow blower only runs on full choke, it’s probably your carburetor. Find the causes and solutions here with my easy-to-follow guide.
There is nothing worse than an engine that won’t start or a snowblower that isn’t running smoothly, especially during the snow season. When the snow arrives and you get old faithful out of storage, be it a single stage or a two stage, only to find it’s not running correctly.
Is it OK to run a snowblower with the choke on? Generally yes. Although running on full choke, in itself, will not cause permanent damage, it is a problem that needs to be resolved for top performance to be achieved and to prevent other issues such as wearing your pull cord out from constantly having to restart the engine.
If you have this or similar running problems or find your snowblower not starting at all unless the choke is on full, read on, I have put together a few simple checks that you can do to get you running smoothly once again.
Contents (Jump to Topic)
First, What Does The Choke Do On A Snow Blower?
As with all small engines, the choke on a snow blower is designed to adjust the airflow into the carburetor to allow a richer fuel mixture in the engine. This is especially helpful in cold conditions when your snowblower won’t start.
Snow Blower Won’t Stay Running: Main Reasons
If your snowblower won’t stay running or the snowblower stalls when the choke is off, there are several common causes.
One of the most common faults causing you to have to use the choke constantly is the carburetor becoming blocked.
When this happens it is usually due to either using old fuel or lack of regular maintenance. This is the primary reason a snow blower only runs with the choke on.
Something most people don’t realize is that regular gas only has a shelf life of 3-6 months! Consequently, over time some of the fuel ingredients will evaporate, making it thick and sticky. When this soupy fuel reaches the carb it builds up to create what we call varnishing of the carburetor.
Even though you may be able to carry on temporarily by running on the choke, this will not resolve the fault and may cause further problems down the line.
Solution To A Clogged Carburetor
Carbs are notorious for clogging up and blocking so it is recommended that you use a spray carb cleaner regularly. Also, emptying your fuel, as part of your regular maintenance will reduce the risk of this happening. With this in mind for the future, you still have a problem for now.
Cleaning a blocked carb can be done relatively easily, although you will need a carburetor cleaner and maybe a carb cleaning kit to do this successfully you do not necessarily have to remove the whole thing.
Please read my blog on How To Clean a Carburetor Without Removing for guidance.
Tips On How To Avoid a Blocked Carburetor
The winter is at an end with summer on its way, you are swapping your snowblower for your lawnmower. Here’s what you can do to save yourself from any further problems when the snow returns.
Use a Fuel Stabilizer
Provided that you always use a fuel stabilizer you will help stop any breakdown occurring in the gas. When the gas breaks down it can become sticky or gunky which may create a fuel blockage in injectors, lines, or the main jet. Along with the fact that it can also cause the carb to become blocked or to work inefficiently.
Drain The Fuel Tank
Strictly speaking, this will not cause you to run on choke constantly, but, nevertheless, I felt it was worth a mention. If you have an adjustable carb fitted then it’s a good idea to check your fuel mixture levels.
Having a fuel mixture that is either too rich or lean can cause the engine to idle too fast or not fast enough, in addition to the engine suffering from hunting (variations in power) and even surging.
Check out how to adjust your specific snowblower carburetor in the manufacturer’s instructions or online for the best adjustment results.
Fuel Cap Blocked
The fuel cap on your snowblower allows air into the tank to avoid a vacuum (or vapor lock) building. If this cap gets clogged it will cut the supply and can be the cause if a snowblower won’t stay running, but there is a simple way to find out if this is your problem.
Simply unscrew the cap a little and if your engine stays running you have found your problem. Unblock using some of your carburetor cleaner or thin wire, and away you go.
Fuel Filter Clogged
Although having a fuel filter fitted on a small engine is a great idea, as I have mentioned above fuel can become deteriorate and become soupy with age. The result of which is that the filter gets clogged, therefore, restricting the flow to the engine.
The solution is to either clean the filter, if possible or, simply replace it (many cannot be cleaned without damage being caused).
Spark Plug Faulty or Sooted
In the event that the spark plug is faulty the symptoms may be that your snow thrower does not idle comfortably. For this reason, you use the choke to solve the immediate problem, but that won’t make it go away.
Although it is OK to run your snow blower with the choke on and you won’t do any permanent damage, the consequence is that you have increased the fuel-air mixture. This in itself may cause sooting to the plug.
It is recommended that you change the spark plug every season, at the very least every other season. Including spark plug inspection in your maintenance regime along with checking your mix is not too rich is a must.
If you do find your spark plug is always dirty, I recommend you change your oil straight away.
Similar Commonly Asked Questions
We hope this article has helped you find why your snow blower stalls when the choke is off or when your snowblower won’t stay running. Remember, looking after your engine and keeping to a regular maintenance schedule will increase its longevity.
How do you know if your carburetor needs cleaning?
When your carburetor needs cleaning on an engine there are signs. The engine may be hard to start, not start at all, lack performance, or run erratically.
This can be resolved by taking the carburetor apart and using snow blower carb cleaner to remove any built-up dirt and debris.
Can you clean a snowblower carburetor without taking it apart?
It is not possible to clean a snowblower carburetor without taking it apart. However, it is possible to keep your carburetor clean without removing it completely.
When should you use a fuel stabilizer?
If your gas is going to be stored for an extended period of time then you should use a fuel stabilizer as soon as you purchase the gas. Gas does not actually have a long shelf life and depending on the type of gas can be as little as 8 to 12 weeks.
Troy Bilt snow blower only runs with choke on
If your Troy Bilt snow blower has to use the choke continuously, the carburetor being blocked is one of the most common reasons. Usually, this is due to the use of old gasoline and a lack of routine maintenance.
Craftsman snow blower only runs on choke
When a Craftsman snow blower will only run with the choke on, it’s best to drain your fuel tank and clean your carburetor with carb cleaner. This usually fixes most choke issues.
Toro snowblower won’t stay running
It’s not uncommon for Toro snowblower to have an issue where they won’t stay running and sometimes stall under load. As with all brands, it’s normally to do with the fuel and air mixture. Empty your gas tank and try cleaning the carburetor properly to remove any debris varnishing.