Is your chainsaw refusing to start? Have you tried every solution you can think of but are stumped as to why your chainsaw won’t start?

There are a number of causes for why a chainsaw won’t start. Before we delve into those, we would like to offer a detailed summary regarding how chainsaws work, along with a step-by-step guide for how to start a chainsaw. Finally, we will name the key components that could inhibit your chainsaw from starting and offer solutions to fix the problem.

How Chainsaws Work

Man using a chainsaw to cut a log

​Image via Pixabay


Before we examine why a chainsaw won’t start, you need to understand how chainsaws work. Chainsaws vary based on their model and manufacturer, with some being powered by gas and others by electricity. Chainsaws may also have different features and accouterments.


That said, all chainsaws have the same basic mechanical system. Chainsaws contain an engine that powers a blade manufactured from a sharp steel alloy. That blade is moved by a chain. Within the chainsaw’s motor, gear wheels rotate the chain so it glides against the guide bar when you use it to cut lumber and tree limbs.

Chainsaws also have a cylinder very much like the ones in cars. The fuel in the chainsaw’s gas tank combines with air in the carburetor. The fuel goes through the cylinder where it is triggered by the spark plug. The fuel burns, and the resulting energy movies the piston.

The piston inside the engine enters and exits the cylinder, pressuring the rod. This connecting rod makes the crankshaft turning gears run so the chain revolves with the guide bar.

How to Start a Chainsaw

Photo of a chainsaw on top of a grass

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Before learning what to do if your chainsaw won’t start, it is worth mentioning how to start a chainsaw. You can do this in a few simple steps.

Put It on a Flat Surface

First, you need to put your chainsaw on a flat surface. The ground will work just fine. Be sure to disengage the bar cover.

Start the Chain Brake

Next, you need to start the chain brake. The chain brake is on the upper handle, so you can easily start it by pushing it forward. Your chainsaw’s chain brake helps ensure that the chain revolves on the bar.

Activate the Decompression Controls

Quite a few chainsaw models have decompression devices, also known as Smart Start. If your chainsaw has this feature, push the decompression controls.

Start the Fuel Pump

While this is not a feature on all models, many types of chainsaws have a primer bulb or fuel pump. Push the fuel bump button a couple times until the fuel appears.

Pull the Starter

To pull the starter rope, make sure your chainsaw is firmly on the ground or another flat surface. Next, position your right foot on the chainsaw’s back handle while using your left hand to secure the upper handle.

Make sure the cutter does not touch the ground until you pull the starter. When activating the starter rope, pull swiftly and smoothly.

Push the Throttle

The final step of starting your chainsaw is to push the throttle. You only need to push it halfway while pulling the starter rope to activate the chainsaw. Once the engine turns on, speed up to keep it running.

If the engine turns off as soon as it starts, you might have to adjust the Master Lever to open the choke. After the chainsaw is operating, push the throttle button to put the Master Control back in its regular setting.

What to Do When Your Chainsaw Won’t Start

Photo of an orange chainsaw

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Corroded Spark Plugs

The first thing you need to check when your chainsaw won’t start is your spark plugs. If the plugs do not spark, they could have experienced corrosion. The spark in your chainsaw helps ignite the fuel inside the cylinder.

However, with continuous use, the spark plug is prone to corrosion and can become worn down. To see if the plug is sparking, take off the plug. Next, take a plug wire and connect it with the metallic section of the engine to see if it ignites a spark.

If no spark happens, you can clean the area with a steel brush, which will usually fix the issue. Occasionally, a simple cleaning is not enough to alleviate the problem and your chainsaw won’t start. If this happens, you will need to install a new spark plug.

Malfunctioning Ignition Coil

Another reason your chainsaw won’t start could be a malfunctioning ignition coil. The ignition coil transmits voltage to the spark plug when your chainsaw is operating.

If you already looked at the spark plugs, cleaned them, and/or replaced the plugs but to no avail, the issue could be your ignition coil. You can check to see if it is malfunctioning by using an ignition coil tester. If the ignition coil is on the fritz, you will need to put in a new one.

Faulty Recoil Starter

When your chainsaw won’t start, another potential culprit is a faulty recoil starter. The recoil starter is made up of multiple components that trigger the engine’s operation once you turn on the chainsaw. These are elements like the rewind spring and recoil starter pulley.

The rewind spring draws in the starter rope once you have pulled it and it has begun to wind on the recoil starter pulley. When the rewind spring is not working as normal, the starter rope will not operate on the pulley, making it tough or completely impossible to start the chainsaw. You can purchase new rewind springs or a new recoil starter set to fix the problem.

Old Fuel in the Tank

You may have already thought of looking at the fuel tank to see if was filled if the chainsaw won’t start. However, you might not know old fuel in the tank could be the reason your chainsaw won’t start. Gasoline is prone to evaporation, so if left in the tank for several weeks, the fuel could go bad and not ignite the engine.

When this happens, drain the old fuel from the tank completely and refill it with new. The engine your chainsaw has will determine the fuel you should fill it with.

For example, the majority of two-stroke engines have an oil and gasoline mixture. Stay away from fuel like automotive oil, boat oil, or gas containing ethanol or methanol. These fuels can corrode the engine.

There is not one specific fuel mixture advised for chainsaws across the board. Look at the manufacturer directions for your chainsaw to see what oil and gas mixture they advise.

Inundated Engine

Another cause why your chainsaw won’t start could be an inundated engine. If your chainsaw has a fuel pump, you likely activated it to get the saw started. Well, if you over push the fuel pump or primer bulb, it could inundate the engine with fuel and stop it from starting.

If you smell fuel when attempting to start your chainsaw, the engine could be flooded. Also, if the spark plug is wet, this is another sign that your engine is inundated with too much fuel.

An easy way to fix this is by opening the spark plug hole and draining it away from you. Disengage the choke by activating the control. Pull the starter rope 6 to 8 times while pushing the throttle. Next, dry excess moisture from the spark plug and put it back in the hole.

Obstructed Carburetor

If fuel sits in your saw’s tank too long, this could be the reason your chainsaw won’t start. Fuel sitting for long periods has a tendency to obstruct the carburetor because the thick residue stays behind even when the fuel evaporates.

The only way to fix this issue is to use a carburetor cleaner to clean out the inside. If cleaning the carburetor does not eliminate the problem, you will probably need to put in a new one.

Clogged Air Filters

Another key culprit for why your chainsaw won’t start could be clogged air filters. When the air filters get dirty, they attract gas rather than air, much like if the choke is on.

Whenever you operate your chainsaw with dirty air filters, carbon builds in the engine. Excess carbon deposits can also occur if you idle the engine too frequently.

It is best to avoid idling the engine, particularly with smaller saw models. Whenever you operate your chainsaw for longer than 5 hours, you need to take out the air filter and clean it thoroughly with soap and water before reinstalling it.


Man cutting a log using a chainsaw

​Image via Pexels

There are many primary culprits for why your chainsaw won’t start, so you may have to test out a few functionalities of your saw to pinpoint the issue. Always be sure to clean and take care of your chainsaw.

Things like tightening chain tension and nuts, clearing off dust and debris, keeping the chain blade sharp, and ensuring that all the mechanisms are well lubricated are key components of maintenance. These items, coupled with the solutions noted above, will help you quickly resolve the problem when your chainsaw won’t start.

​​Featured image ​via Pixabay