Snow Blower Won't Start Up? Here Are Some Troubleshooting Tips

Sometimes, the Issue Is a Simple One


The Spruce / Jesi Lee

Winter is here, and now you find yourself with a gas snow blower that won't start, 12 inches of snow to clear, and no desire whatsoever to shovel it off your driveway (or even to try to find someone else to shovel it). This is when you start kicking yourself for not following up on that "check the snow blower" note on your to-do list. But all is not lost.

Here are some troubleshooting tips that could save you a lot of time (and perhaps a trip to the repair shop). Using process of elimination, work your way down the list until your start-up problem is remedied. If you have any doubts regarding your ability to perform these tasks without causing harm to body or property, have your unit serviced by a professional.

Check the Fuel Tank

Make sure your fuel tank isn't empty (check the oil while you're at it) and that the gas isn't dirty. You want to start off on the right foot with clean, fresh fuel. You can tell if your fuel is old if it has turned into a varnish-like coating in the carburetor. Moreover, if you didn't add a fuel stabilizer to the gas before you stored it, the fuel might have lost its volatility. If this is the case, you'll need to drain the system through the carburetor. You can eliminate such concerns by switching to an electric snow blower.

Once it's drained, you can pour in fresh fuel and a fuel stabilizer. If old fuel has gotten into the carburetor, then the carburetor likely needs to be cleaned or replaced by a professional. Fuel lines and filters can also get all gummed up due to dirty fuel and may need to be replaced at the shop.

Set the Fuel Shutoff Valve to 'On'

The correct position of the switch for the fuel shutoff valve to start your snow blower is something that could easily elude your memory if you haven't used your equipment for months. If this switch is in the OFF position, then flip it to the ON position. It is easy to do, but it's also easy to forget.

Check the Safety Key Switch

We are not done checking switches. Some snow blower engines have a safety key switch (you may be familiar with similar starting keys on lawn mowersand a red toggle switch. Check to make sure that the key is properly inserted into the holder and that the red toggle switch is in the RUN position. Failure to flip either one of these switches will result in an inability to start up your snow blower. Worse yet, you might flood the engine if you attempt a start-up under such conditions.

Try Starting in 'Full Choke Mode'

Athletes despise the word "choke." But there's no shame involved in using the choke on your snow blower. In fact, to start up a snow blower when the engine is cold, you want to use FULL CHOKE mode. Also note that if the thermometer outside reads above freezing, you may not want to prime the carburetor, as this may flood the engine. It may be best, in this case, to use just choke and skip priming altogether.

Check Throttle

If you have a throttle on your snow blower, check to make sure the throttle is positioned to three-quarters speed or higher.

Examine the Spark Plug

All right, let's say you've performed all of these steps and the engine still isn't firing up. Remove the spark plug to check it. You're looking for three issues here:

  • Fuel that doesn't belong on the spark plug
  • The correct gap
  • A crack in the porcelain part of the spark plug

Regarding the first issue, if the spark plug is wet, that means it has been flooded with fuel, which is not something you want. If you find the spark plug in this condition when you remove it, turn the engine over several times (with the spark plug still removed). This should remove the fuel from the spark plug hole that had seeped in during the flooding. Clean off the spark plug and put it back in (or if it doesn't clean up to your satisfaction, install a brand new one).

Regarding the second issue, check for the correct gap and, if necessary, adjust it. 

Regarding the third issue, cracking indicates the spark plug is damaged beyond repair and must be replaced.

Even if the spark plug, itself is in good shape, there could be a problem with your ignition coil. There are spark plug testers and ignition coil testers that can be helpful in diagnosing issues keeping your snow blower from starting up. 

Finally, try to start the engine again, but without using the choke.

Check the Starter

If you're having trouble starting your machine and have ruled out everything else, the fault may lie in the starter. Some snow blowers have electric-start engines. The electric starter may break over time, in which case it would need to be replaced at the shop.

If you've completed this checklist, but your snow blower still won't start up, you'll need to take it to a professional servicing dealer or else buy a new snow blower.