How to Start a Chainsaw that Won’t Start (7 Reasons Why Your Chainsaw Won’t Start)

Many chainsaw owners have the same problem when starting their chainsaw.

However, their chainsaw won’t turn on without spark or fuel. Is your chainsaw also dragging you into situation as well?

If you are also facing this type of problem. If so, don’t worry.

In this chainsaw guide, We highlight most of the common starting issues and their solutions. No matter how hard you try, there are many possible causes.

You’ll learn how to start a chainsaw that won’t start, and how to fix it. You’ll also learn my top tips to prevent this from happening ever again.

So, Let’s get started!

1. Check on a Fuel

Gas gets overlooked a lot. We still assume there’s a major problem with the oily parts of our kit when very often the problem is pretty easy to fix.

Gas goes stale, and you may be surprised to know that it can go off in as little as one month. It loses its Oomph, the symptoms include, no starts, lacks of power bogging down, stalling, surging, and everything between.

Lots of gas today is a blend of ethanol, this type of fuel attracts moisture, and that invites trouble.

When a customer shows up in my workshop complaining of  a lazy starting saw after sitting, I’ll always suspect bad gas.

I have a pretty good nose for bad gas. If you suspect that your gas is older than one month, then go ahead and empty the gas tank and fill it with a fresh mix of gas and two-stroke. For many saws, this is enough to get the saw recommissioned.

Gas Shot

If the saw doesn’t start after filling it with fresh gas, I will try to inject gas directly into the carburetor. Sometimes, bad gas may need a little help to drain from the carburetor.

Three outcomes can be expected from the gas shot.

You can now try the gas shot. Remove your air filter. Most saws don’t need any tools. Drop a capful (thimble-sized) of gas into your carburetor.

Outcome 1: Saw starts and runs, you are lucky, and your job is done sir.

Outcome 2: You can repeat the process 2 to 3 times. If it continues to stall you will need to remove the carburetor and clean it (see clogged carburetor).

Outcome 3: Saw fails to attempt to start. An ignition system fault could be causing the problem (see plug fault).

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2. Take a Look at the Carburetor

Unfortunately, this patient will need surgery. This is likely because the stale fuel has clogged up small fuel passageways and congealed in the carburetor. It is not unusual to have to take out the carburetor only to find that it has become too clogged.

Manufacturers of carb kits include gaskets and gas needle valves and arms. While it’s best to replace them as you are going to be disassembling the carburetor anyways, it is also possible to reuse the exact parts.

As an alternative just go ahead and change the complete carburetor as you’ll find in most cases  carburetors aren’t ve any doubts about the carb I’m working on, I’ll bounce for a new one.expensive. All new carburetors come with a guarantee. They are tested and tuned before being shipped.

Tools You’ll Need

Some chainsaws are difficult to remove the carburetor, but most people will find it easy.

However, working with saws is not the same as working on your car, truck or mower. These parts are small and require a lot of patience. If you have Shrek hands, this might be a good idea to skip.

Some saws will require special carburetor adjustment tools. but other than that just a selection of sockets, carb cleaner, screwdrivers, carb cleaning tools, and my top tip – gas stabilizer additive to stop this from ever happening again.

Replacement Carburetors

You should ensure that you order the right model if you decide to replace your carburetor.

The power output of your saw is calibrated for the carburetor. Although a family of carburetors may look identical, they are all different.

You’ll find most saw manufacturers don’t make their own carburetors. They use trusted third-party carburetor manufacturers like Walbro or Zama.

After you’ve removed the carburetor, check for the model and make stamped on the body.

After fitting a new carburetor or cleaning it, make sure you clean the gas tank and install a new gas filter.

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3. Spark Plugs Might not be Sparking

Plugs are hard workers and live in hostile environments. They are right in the middle of the action. They are found in hot cylinders next to hot mufflers, so it is no surprise that they rank third on the list. You’ll find plugs are pretty tough components, they can work tirelessly for years and not lose a beat.

Although a plug should be replaced at the beginning of each season, I live in real life and most owners will not give it a second thought as long as it is doing its job.

You should make sure you get the correct plug for your saw. Plugs come in different thicknesses, lengths and heat ranges.

For the correct part number, check your make and model.

Checking Spark

 spark without the use of a test instrument.

  • Remove the spark plug
  • To ensure a strong connection, I use jump leads to ground the plug body against the saw body.
  • Turn the switch to “On” to start the saw.
  • Observe the spark plug for spark

You’re a spark! It’s all good.

No Spark From Plug

It doesn’t necessarily signify that there is a problem.

If there is a gap between the electrode and the tip of your plug, you should inspect it. You can open the gap with pliers, or a flat screwdriver, if it is not closed.

If the plug is not free of oil or carbon, clean the plug using a wire bru. Check for spark again.

Swap it if you have a spare or donor plug or a known good donor test plug . Turn the engine over and check for spark. If spark is still absent, check the armature (see below).

4. See if the Engine is Flooded

how to start a chainsaw that won't start

What is flooding? It is simply too much gas in an engine’s combustion chamber. The spark plug does not ignite the gas. Instead, excess gas extinguishes it. Sparkle equals no fun

Why does this happen? Flooding is often caused by engine overheating. Flooding can often be caused by an underlying problem such as bad fuel, bad spark plugs, excessive choke use, or a defective carburetor.

Flooding can be a problem if a saw isn’t maintained properly.

How can you fix it? There are three options to fix a flooded chainsaw.

  1. Let the saw rest for 30 minutes and any excess gas will evaporate.
  2. Turn off the spark plug and dry it. Finally, turn the engine several times to dry the piston. Reinstall the spark plug and then try it again.
  3. Turn the switch to “On”, open the throttle, turn the choke to “Off”, and crank the engine. The saw should start after the third pull.

How can flooding be prevented? Make sure you have fresh gas and your saw are in top shape.

5. Inspect The Air Filters

Air filters protect the engine from any particles. However, the air filter is also where the fuel and air will be mixed. The engine will struggle to obtain the oxygen it requires if the filter is blocked.

As part of their job, filters can get clogged up or dirty over time. Due to this, regular maintenance is necessary to keep filters clean. It’s a good idea if your filter is old and/or very dirty to replace it.


6. Check the coil and springs

What we have looked at already covers the vast majority of times when a chainsaw won’t start. If you’re still left scratching your head then you need to delve deeper into the system and the problem might be with the ignition coil or rewind spring.

The ignition coil sends the electricity through to the sparkplug and without this, they simply won’t spark. They have testers for ignition coils available but you can also use a multimeter. If that’s the root of the issue then you simply need to replace them and your chainsaw will be working once again.

The rewind spring can also be a problem as this is what’s meant to allow you to repeatedly pull the starter cord. Unfortunately, this can end up being a very big issue as unless you can replace the spring, the recoil starter assembly might have to be completely removed.

The recoil starter assembly might also be a part of a bigger problem. One way to test it is to remove the assembly and pull the cord, to make sure the tabs are working correctly. If they aren’t then your only solution is going to be completely replacing the assembly.

7. Check The Armature

Failing to properly assemble the coil (or armature) is a common problem. The spark plug requires high voltage to ignite because the armature and flywheel produce it.

Two ways are common for armatures to fail. They may work fine when the machine is cold, but then they will stop working as soon as it heats up. They can also stop working for a short time.

Testing The Armature

The spark plug test is the first step in testing the armature. However, it would be a good idea to use a proper tool for testing the ignition system. The test tool will load up the armature, and reveal any weaknesses. Our hack with the plug is not foolproof.

This page contains a test tool and other useful tools for small engine repairs.

It’s easy to test, just go ahead and:

  • Remove pull assembly cover (4 screws usually)
  • Remove coil control ground wire
  • Refit pull assembly
  • Check spark as before

Is there still no spark? Replace the armature.

If spark is still present, you can check for damage to the wiring or shorting of the on/off switch.

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