Why Chainsaw Won’t Start When Hot? Solutions & Maintenance Tips!

If your chainsaw won’t start when it is hot, it is not a strange issue. This problem is not an evidence that your chainsaw is not of good quality; rather it happens in chainsaws from many trusted manufacturers.

The occurrence of this issue is not affirmed to one particular reason; it can be a result of multiple factors. Let us examine the causes, solutions, and required maintenance processes that can solve the problem and keep your chainsaw in great condition.

Why is My Chainsaw Not Starting When Hot?

Normally, the chainsaw starts, no matter whether it is hot or cool. But in circumstances like heat accumulation inside the machine, the problem may appear. This issue can majorly be caused by faults with the coil or carburation.

The issue is more common in summer than the winter, that’s because of the atmospheric heat playing a role.

It is more recurrent in old models of chainsaws due to altered gas flow or issues with the spark plug. Replacing spark plugs and clearing gas lines can directly reduce the frequency of the problem, but it can have its root deeper than you expect. Let me clearly state the possible causes and how to approach them.

Vapor Lock is a Common Cause

Vapor lock is caused by the lack of adequate ventilation inside the machine. If the heat builds up excessively and creates an elevated vapor level when there is no adequate ventilation, vapor lock is a possible consequence.

To prevent this from happening, you should ensure the vent hole of the fuel tank is clean. If you suspect any issue with the ventilation system, open the gas cap occasionally to allow the gases escape.

Problems with Ignition

A clogged spark plug can get in the way of proper ignition. Make sure the plug is not covered with black sludge of carbon particles. This is a thing that’s out of your reach. These will build up over time because of the constant use of the chainsaw.

Apart from the spark plug, ignition mode can be problematic, probably due to its coil. To confirm you don’t actually have a problem with fuel supply, open the choke valve under the air filter, spray some starter fluid into it, and see if the chainsaw starts.

Problems with Fuel Supply System

The engine can get blazed at high temperatures when fuel is poorly supplied into the carburetor. Such high temperature situation will prompt the engine to stop working. Leading causes of this scenario include a dirty fuel filter or the hose losing seal with the carburetor (due to the heat). To combat this issue, adjust screws of the carburetor, and replace filters and hoses regularly. 

why chainsaw won't start when it is hot after a run

How to Solve the Problem of Chainsaw Not Starting When Hot?

You can run quick checks and servicing that will get your chainsaw running again. Let us discuss the steps involved.

Step 1: Remove Vent

Start the engine. Let the engine run till it stops. Try to run it again and see if starts or not. Once such a problem has been established, then start the following procedure.

Remove the little vent connected to the fuel line and start the chainsaw to see if it works. If that works, stop the engine and install a brand-new vent. If that doesn’t work, proceed to the next step.

Step 2: Use Carburetor Cleaner

Check the top of the carburetor and get the air filter removed. Apply some carburetor cleaner to the exposed carburetor, then start the chainsaw. If the chainsaw starts and then goes off again, the carburetor needs a replacement.

Step 3: Replace the Carburetor

Detach the fuel line supplying the carburetor to remove the screws that make the carburetor attached to the engine block. Get carburetor twisted and set the side of the linkage of throttle off. This process is the prerequisite for changing the carburetor. Use the two screws to attach the new carburetor, get the throttle linkage slide on again, and then plug in the fuel supply. If the problem persists, move on to the next step.

Step 4: Spark Test

You need a spark plug tester for this step. Detach the wire that is connected to the spark plug. A side of the tester should be linked to the spark plug wire, and the other end is to be linked to the plug itself. Then engage the starter cord, pull it rapidly to see if the tester produces sparks. If there is no spark, then the coil is bad.

Step 5: Replace coil

Take the plastic housing attached to the engine block out and expose the coil. Disconnect the coil wire and replace the old coil with a new one. Tighten all the hex bolts to keep things in place. Make sure there is a small gap separating the coil and flywheel magnets. Use a wrench to tighten hex bolts while you connect the coil wire and plastic housing again.

These steps, if followed properly, should have your chainsaw working as desired. It is all a series of strategic troubleshooting and a bit of trial by error.

Chainsaw Maintenance Tips [Maintain Like Professionals]

A properly maintained chainsaw will definitely have less issues. Here are a few professional tips for keeping your chainsaw in shape.

Cleanliness Is Next to Efficiency

Dust, dirt, and debris will do your chainsaw no good. Such particles can get things clogged up and create serious problems for you. A combination of water and ammonia can clean your dirty chains. Soak for some minutes and scrub with a good brush.

Keep Your Blades Sharpened

This is a primary requirement since the blades are the contact agents that do the work. Make sure they are never dull or blunt.

Make Lubrication Is A Duty

Oiling the chainsaw reducing friction and less friction results in fewer damages. Less friction also means less heat that can result in the chainsaw refusing to start.

Keep Gas Supply Fresh

If your last gas supply has been for a while, gas may experience degradation processes that are not good for your engine. Make sure you supply fresh gas to the chainsaw regularly instead of reserving large amounts down for its operation. Degraded gas can destroy the engine of the chainsaw.


Maintenance should come first as it ensures safety and prevents the occurrence of faults. Most possible chainsaw faults can be easily troubleshot and attended to. It all boils down to you being familiar with the chainsaw mechanisms. Know your chainsaw well and know the steps to take; you will surely get a good result.

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