How to fix vapor lock in a chainsaw

Chainsaw engines face the vapor lock issue, and the tool is difficult to start and work.

It is because the engines of the chainsaw get overheated with use.

The overheating affects the life of the components and results in a vapor lock that starting the tool becomes challenging. 

How to fix vapor lock in a chainsaw

What is a chainsaw vapor lock?

A chainsaw vapor lock is a trouble that begins after a run. The vapors of the gasoline accumulate in the fuel lines.

Thus, it deprives the engine of receiving enough fuel.

Besides, in most cases, the fuel tank cap opens and allows the vapor to escape.

Make sure to run the engine idle before the shutdown for a few minutes.

How to know if a chainsaw engine has a vapor lock

If a chainsaw engine experiences a vapor lock, it will work perfectly, but the moment it starts heating, it will act as though it runs short of fuel.

While, sometimes, it fails to start even after you turn the engine off.

Vapor lock is when gasoline vaporizes in the fuel tank and the fuel lines excessively.

As the chainsaw heats, the vapor pressure increases in the fuel lines.

Thus, the heating worsens, and the saw starts running at WOT ( wide-open throttle).

With the vapor pressure building up, the carburetor has trouble extracting the gasoline due to the backpressure of the vapors which hinders the fuel line.

As a result, the engine starves due to fuel and does not start once it is shut after an operation where it gets heated.

Most fuel tanks feature vents allowing fuel vapors to escape into the atmosphere.

Therefore, the vapor pressure does not escalate much triggering a vapor lock.

In case, you experience an overheated chainsaw that fails to start, you may check the tank vents to understand if anything is clogging.

Also, during vapor lock, the chainsaw begins fine if it is cold and functions perfectly.

As the tool starts heating up, it shows signs of bogging down and gives a run-out-of-fuel feel.

If so, you may shut the engine off and restart it, but it will not start. It means it is time you confirm the engine has a vapor lock.

How to fix a vapor lock in a chainsaw

Fixing a chainsaw vapor lock means allowing your chainsaw to cool before starting, and here are the ways:

Fastest Way:

Fuel vapors are trapped in the fuel lines and the carburetor. These vapors exert back pressure, obstructing the fuel flow.

The fastest way is to remove the vapor by letting them escape into the atmosphere.

You can do this by opening the fuel tank cover and letting the vapor escape. 

As the pressure of the vapor falls, the fuel flow eases down, and the engine starts. It is not the safest method.

It may turn risky if you let out highly pressurized fuel vapors escape into the atmosphere.

It is because it can ignite and start a fire, in a closed environment. Besides, if these vapors are hot, they may cause skin burns.

Safest Way:

The safest way is in ascertaining these vapors cool down. Once it cools, inside the fuel lines it will condense.

You may stop your engine and allow it to cool for a while.

If you try to start immediately, it may be more time-consuming. To make the process fast, you can pour cold water on the engine area and the carburetor.

It will help cool down the vapors and fix the vapor lock.

Helpful Tip:

Some users turn on the choke and set it to a rich setting their carburetor encountering a vapor lock.

They do so to enrich with more fuel the mixture that was facing obstruction due to vapor lock.

However, there is the possibility that after fixing the vapor lock, your engine may run richer and have trouble running.

It may unnecessarily increase the fuel consumption of the device.

Avoid adjusting the carburetor to a lean setting, as it may cause overheating and aggravate the vapor locking effect.

How to stop a chainsaw vapor lock

Preventing a chainsaw from vapor lock is possible if you avoid overheating or running it lean.

Ensure you allow the engine to stay idle before shutting it off.

Vapor locks may be frustrating to finish.

You may save the trouble of fixing repeatedly on follow some useful tips and avert the vapor locks on your chainsaw:

1. No Running at WOT:

Running at wide-open throttle (WOT) your chainsaw results in overheating.

The heat generated boils the gasoline and causes a vapor lock.

Operating at WOT for a longer time may damage the engine components with the guide bar and chain.

2. No Running Lean:

Users keep their new chainsaws running lean to save fuel and provide them with high RPMs to facilitate cutting tougher wood.

The screws H and L at the carburetor mix rich or lean as per the adjustment.

It is good to know that mixing lean ratios may cause the chainsaw to overheat and end in a vapor lock.

3. Idling Before Shutdown:

Restarting the chainsaw results in a vapor lock, and is a result of using it after the chainsaw is already hot.

Before shutting the engine, let it stay idle for a few minutes.

It will drop the engine temperature gradually and cool down the fuel vapors.

If you follow this, your chainsaw will never get vapor-locked, and there will be no trouble in restarting the chainsaw.

4. Check the Fuel:

Chainsaw-related issues are due to the transition from winters to summers.

Fuel blend is lighter in winters, it vaporizes at lower temperatures, the same is with spring onset, and the temperature rises.

So check the fuel to avert issues relating to vapor lock.

Wrapping up

Fixing vapor lock in a chainsaw is possible.

Allow 10 to 15 minutes for the chainsaw to cool, and the vapor pressure will subside.

You may fall into trouble in case the engine does not function suddenly.

Do not worry; let it stay idle for a few minutes. It will release the heat and fix the vapor lock.

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