A chainsaw is a productive tool to cut wood for your next bonfire or to heat your home. It’s also a good tool to clean up after the latest storm. Running old gas through a chainsaw is a big culprit to a chainsaw not running or starting. There are also many other items that can prevent starting.
A Husqvarna chainsaw won’t start when it doesn’t have sufficient air, fuel, or spark to form combustion. A bad on/off switch, old fuel, plugged fuel filter, clogged fuel line, dirty carburetor, plugged air filter, plugged spark arrestor, bad spark plug, or faulty ignition coil can keep a Husqvarna chainsaw from starting.
Keep reading for additional reasons your chainsaw won’t start. Remove the spark plug wire before beginning any repairs.
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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 Husqvarna Chainsaw Will Not Start
Bad Switch or Wrong Setting
The switch on your Husqvarna chainsaw must be placed in the on position to start. If you find that is in the off position, flip it to on.
A faulty switch or bad ground wire can be the reason a chainsaw won’t start. Use a multimeter to test the switch. Replace a bad switch. Repair or replace a bad ground.
Old Fuel
Gas doesn’t last forever. In fact, it lasts a relatively short period of time before it begins to break down and become less effective. Most gasoline today has an alternative fuel added to it to make it a little better for the environment.
This fuel, made of corn or another high-starch plant, is known as ethanol. While ethanol is usually okay to run in most vehicles, it is not good for small engines like the one in your Husqvarna chainsaw.
Ethanol attracts moisture from the air to the fuel system. The ethanol and water mixture will leave behind a sticky varnish that can gum up the fuel system and cause clogs and failures.
Because gasoline begins to break down as soon as 30 days after purchase, it’s important to use the gas within this period. If you are unable to consume it, add a fuel additive to stabilize the gas so it lasts a little longer.
Husqvarna chainsaws require gasoline and oil mixed at a ratio of 50:1. Use a gas that has a minimum octane rating of 89 and a maximum ethanol content of 10%.
Avoid gas with high levels of ethanol content like those sold as E15 and E85. These fuels have up to 15% and 85% ethanol content respectively. Read more about the gas to use in chainsaws in “This is the Type of Gas and Oil Husqvarna Chainsaws Use“.
Drain any old fuel remaining in your Husqvarna chainsaw. Fill with a fresh gas and oil mixture. Add a fuel additive like Sea Foam Motor Treatment or STA-BIL to help reduce moisture and clean the fuel system.
Note: Some 2-cycle oils will include fuel stabilizers. Depending on the brand, it can be effective anywhere between 30 days and 2 years.
Incorrect 2-Cycle Oil Mix
As mentioned before, Husqvarna requires a fuel that is made up of a mixture of gas and oil. Placing straight gas in the chainsaw will damage an engine and may result in you having to replace it.
Straight gas runs very dry. It can cause the engine to seize due to the lack of lubrication.
Mix gas with a premium 2-cycle engine oil like Husqvarna XP or any other equivalent oil that is ISO-L-EGD and JASO M345 FD certified.
Ethanol-free fuel
Because ethanol in fuel negatively affects the performance you receive from your Husqvarna chainsaw, using an ethanol-free fuel is best, but more costly. Husqvarna makes a premixed fuel that is ready to pour in the fuel tank.
This is a great option to have sitting on the shelf so you don’t run out of fuel and have to make a trip to the fuel station and then have to spend time mixing oil into the fuel.
Plugged Air Filter
The air filter is an important component used to protect the engine. A filter keeps dust and debris from passing through the filter and into the carburetor throat preventing wear on the engine.
When the air filter isn’t regularly cleaned or replaced, the buildup of dirt can be so significant that good airflow isn’t able to pass through it. A plugged air filter will prevent your Husqvarna chainsaw from starting.
It’s good practice to replace your air filter annually and clean it several times throughout the season if you’re the average homeowner. If you use your chainsaw a lot, you’ll have to clean and replace the filter more often.
Take time to inspect your air filter to prevent overheating the engine and causing damage. I know, this is one more step, but it takes less than a minute to check the condition of the filter and can prevent engine damage. If the filter is extremely dirty or damaged, it must be replaced.
Never run a chainsaw without an air filter. You may get tempted to run your Husqvarna just a little longer to finish your task until you get a new air filter replacement, but doing so puts the engine at risk of damage.
Steps to clean a Husqvarna chainsaw filter:
- Remove the engine cover.
- Remove the air filter.
- Wipe out any dirt from the air filter housing.
- Brush dirt from the filter or shake it to remove the dirt.
- If needed, wash it in a mild dish detergent and water solution, rinse until the water runs clear, and allow the filter to completely dry.
- Reinstall the clean filter. Purchase and install a new air filter if the old filter is extremely dirty, damaged, or is unable to properly seal leaving a gap where dirt can bypass the filter.
- Reattach the engine cover.
Bad Spark Plug
The spark plug provides the spark required to start and keep the chainsaw running. The spark plug is a wear item that should be changed annually for the casual user. If you use your chainsaw regularly, you may need to change it as often as monthly.
Inspect the spark plug and clean it with a wire brush in between replacements. A dirty spark plug can cause the spark plug to misfire causing running issues.
Replace a spark plug if you find it is very dark in color, has a burnt electrode, or broken porcelain. Make sure the spark plug is gapped to Husqvarna’s specification and the spark plug wire is securely attached.
Faulty Ignition Coil
If the spark plug is in good condition, but you still aren’t getting spark, check the ignition coil. The winding on the ignition coil can separate and short out.
When this happens, the spark plug won’t get the voltage required to create a spark. This will cause your Husqvarna chainsaw to fail to start.
Identify a bad ignition coil using an ohmmeter to check for a break in continuity. Replace the ignition coil if you find a break.
Plugged Fuel Filter
Like the air filter is used to keep dirt out of the air intake to prevent wear on the engine, the fuel filter is used to keep dirt out of the fuel system.
The fuel filter on a Husqvarna chainsaw is located in the fuel tank. It is attached to the end of the fuel line to strain fuel before it enters the line.
When the filter isn’t changed regularly or when dirty fuel has been used, it can become plugged restricting the amount of fuel that is able to pass through the filter.
When your Husqvarna isn’t able to get a sufficient supply of fuel, it will fail to start or run sluggishly. Replace the fuel filter annually and more often if you use the chainsaw regularly.
Replace a Husqvarna chainsaw fuel filter:
- Wipe around the fuel cap to keep any dirt from falling into the fuel tank when removing the fuel cap.
- Remove the fuel cap.
- Use a clean bent wire to hook the fuel line and pull the fuel filter out of the tank.
- With one hand securely holding the fuel line and ring clip, pull the filter out of the fuel line with the other hand.
- Install a new fuel filter by inserting the male end into the fuel line making sure the ring clip is securely holding the fuel line to the filter.
- Place the filter in the fuel tank and reinstall the fuel cap.
Bad Primer Bulb
A cracked primer bulb that won’t fill up with fuel won’t function correctly to get fuel to the carburetor. Replace with a new primer bulb.
Clogged or Punctured Fuel Line
Letting fuel sit in your Husqvarna and age can cause buildup in the fuel line restricting fuel flow. You can try to remove the blockage and clean the line using a carburetor cleaner.
Remove the clogged line, spray carburetor cleaner into the line to loosen up the clog, and blow compressed air through the line to remove the clog.
If you are unable to successfully remove the blockage or you find the fuel line is damaged, punctured, or cracked, it’s best to replace it with a new fuel line.
Dirty Carburetor
The carburetor regulates the amount of fuel that is mixed with air to create combustion in the cylinder. Old fuel will gum up and clog the carburetor so it no longer functions as designed. This can keep your Husqvarna from starting.
If you are a little mechanical you should be able to handle cleaning your carburetor. Clean the carburetor by taking it apart and using carburetor cleaner to clean it.
If the carburetor does not function after being cleaned, you may need to rebuild it or replace it with a new carburetor.
Bad Recoil Starter
Your Husqvarna chainsaw uses a recoil to start the engine. A bad pulley; loose or missing spring; or broken clips can keep your recoil from working.
You can attempt to replace the spring and restring the recoil. If it does not work because other components in your recoil are damaged, such as the clips or the pulley, you are better off just replacing the recoil assembly.
Plugged Spark Arrestor
The spark arrestor is a small screen that can get plugged with soot. A plugged spark arrestor will prevent airflow causing your Husqvarna chainsaw not to start.
Remove the spark arrestor and clean it with a wire brush. Replace the mesh spark arrestor screen when you are not able to clean it sufficiently or if it is damaged.
Never run your Husqvarna without this screen or with a screen that has a hole in it.
Flooded Engine on a Husqvarna Chainsaw
The engine can become flooded when the choke is in the closed position and the starter rope was pulled many times.
It can also happen with the switch off and the starter rope being pulled multiple times or when the primer bulb is pushed too many times.
How to Fix a Flooded Engine on a Husqvarna Chainsaw
- Remove the spark plug.
- Place the chainsaw on its side. The spark plug hole should be pointed away from you.
- Pull the starter rope 6 to 8 times.
- Reinstall the clean spark plug.
- Start the chainsaw.
Still Having Troubles With Your Husqvarna Chainsaw?
As the owner of a Husqvarna chainsaw, you’re going to run into problems with it occasionally. This is true of all chainsaws.
To help you quickly identify the cause of your problem and how to fix it, I’ve put together a handy reference guide. You will find charts with problems and solutions to many common Husqvarna chainsaw issues along with links to information in more detail.
Check out Common Husqvarna Chainsaw Problems for help solving problems with your chainsaw not starting, the chain not turning, the engine dying, a loss of power, and more.