The Generator Choke – [How and When Should I Use It?]

The choke/lever is a vital organ of the generator that allows us to fire up the generator in an instant even in freezing temperatures.

The purpose of the Generator choke is to control the flow of air so that a rich fuel-to-air ratio will be provided to the combustion chamber for an instant startup.

This guide is all about answering your burning queries like how to use a choke on a generator, Why and when should I use it and whether can I leave the choke ON/CLosed for a longer time.

What Is a Choke on a Portable Generator?

A generator choke is designed to control the flow of air into the carburetor of an internal combustion engine.

When the engine is cold the generator’s choke blocks the air supply to the carburetor so that the combustion chamber should be Fed with the rich fuel-to-air ratio (more content of fuel) for a quick startup even in the freezing weather.

The choke of Most portable generators can be opened and closed by a cable that goes to the handlebar/Knobe. Also, the choke should be open once the engine is warmed up, this will ensure the proper air-to-fuel mixture to provide maximum output and efficiency.

How to Use Choke on a Generator?

Before using the choke we recommend going through the user manual to find out the manufacturer’s instructions.

1. Open the Fuel Valve of the Generator:

Make sure to turn the fuel valve to the ON position.

Fuel valve
Fuel valve

2. Locate the Choke Lever/Button:

Mostly choke is located near the air filter’s assembly; you will find a lever or a knob with a label/lettering as seen in the picture below.

label of the choke
label of the choke

3. Keep the Choke at ON/Closed Position:

Before starting the generator keep the choke/lever in the ON/Closed Position so that a rich fuel-to-air ratio will be fed to the piston for quicker Startup, Also keep it running for a few minutes with the choke ON position if there is extremely cold outside.

4. Keep the Choke at OFF/Run/Open Position:

After warming up the generator make sure to gradually drag the lever to the OFF/Open position, this will make sure a balanced air-to-fuel mixture should be fed to the combustion chamber to ensure a greater output with decent efficiency as well. In addition to that the chances of overheating will also be reduced as the generator constantly inhales the fresh air

Choke Positions
Choke Positions

5. Connect The Load:

Once the generator is in normal condition you can connect the load as per its size and wattage.

Recommended Read: How to Fix the Generator that only runs on Choke?

What Does a Choke Do on a Generator?

During the cold start, the choke/lever of the generator restricts the flow of air to make a super-rich fuel-to-air ratio for faster startup.

Due to the blockage of air to the carburetor a volatile explosion will happen as more fuel is available to burn.

Also once the engine is warmed up the choke can be turned OFF/Open to maximize the efficiency and output of the generator by providing a sufficient amount of air.

How Does a Choke Work on a Portable Generator?

The generator choke contains an air passage that can be blocked or unblocked simply by pressing the pulling the knob or sliding the lever.

The sole purpose of a choke is to control the flow of air to the carburetor so that an enriched fuel mixture can be created for a quicker startup.

During the colds we put the choke to the ON/Closed position so that the flow of air can be resisted and a rich fuel-to-air ratio will be created for instant startup, however After warming up the engine we gradually slide the choke to the OFF/Open position to ensure the balanced airflow for the maximum power output and efficiency as well.

When Should I Use the Choke?

During the freezing winters the choke is the only weapon to start the generator in an instant; you just need to block the airflow to provide more fuel to the combustion chamber.

Also after warming up the machine, the airflow to the carburetor could be increased by the help of the choke to enhance the output and efficiency by providing a desired fuel-to-air mixture.

In addition to that, sufficient airflow through the coke to the combustion is also a vital ingredient to restrict the engine from overheating as well.

NOTE: We recommend starting the generator with the choke ON/Closed position (1/2-3/4 Closed is recommended); however after warming up you have to OFF/Open the choke for better runtime and outputs.

Recommended Choke Position When Starting the Engine

We recommend keeping the choke at the ON/Closed position before starting a cold engine machine, especially in freezing temperatures.

This will ensure the combustion chamber should have enough fuel to fire up the generator in an instant.

NOTE: The choke shouldn’t be fully closed (1/2-3/4 Closed is recommended) as the combustion process needs a certain amount of fuel and if it’s not getting sufficient oxygen, improper combustion will occurs and as a result engine floods.

Recommended Choke Position Once the Engine Is Hot/Warmed Up

After warming up the engine, the choke position should be OFF/Open so that a proper air-to-fuel ratio should be fed to the combustion chamber to not only increase the power out but also the runtime as well.

Besides the output and efficiency, sufficient airflow to the combustion chamber will make sure the engine shouldn’t overheat at any cost.

NOTE: don’t ever fully open the choke, especially in freezing temperatures, gradually slide the lever or pull the knob otherwise the generator may turn off because of the extremely cold weather.

At Which Position Should the Choke Be on a Generator?

Generator Engine StageIdeal Choke Position
Starting a Cold Engine in freezing Temperature1/2-3/4 Closed
While the Generator Is Running in Normal ConditionOpen
Restarting a Previously Warmed Up EngineOpen

Can You Leave the Choke Closed on a Generator?

No, the choke should be adjusted to the open position once the engine is warmed up. Since the purpose of a choke is to control the airflow if the combustion chamber is continuously fed with the rich fuel-to-air mixture and there is no air for breathing, the Generator becomes overheated, or even severely damages the engine.

For better output and smoother operation, the choke should be slightly or fully open depending on the outside temperature.

Is It Safe to Choke a Generator?

Yes, as long as you know how to use the choke in the correct way you are good to go, however, if you don’t have prior experience, we recommend going through the user manual first.

How Do You Know if the Choke Is ON or OFF?

You will find the labeling/lettering on the top of the choke that properly indicates the ON and OFF condition of the choke.

In addition to that the engine’s sound will also be a main indicator as with the choke ON/Closed position the generator sputters, however at OFF/Open Position the engine runs smoothly unless the engine is super cold.

Final Words

As I have mentioned above that the choke is the tool to fire up the generator as quickly as possible, however, the choke shouldn’t be ON/Closed for more than 1 to 2 minutes as the engine needs a certain intake of oxygen and airflow not only for the combustion process but also to cool down the engine as well.

For a better and smoother operation, we recommend reading the Operating manual and look for the manufacturers’ instructions about the usage of the choke as per the anatomy of the particular machine you own.

I hope I have delivered what I promised, if I am missing something please comment below, I will be more than happy to assist you!

Frequently Asked Questions – [FAQS]

What Happens if Choke Is Left On?

Due to the less or no intake of the air the engine of the generator becomes overheated or even damaged at all.

How Long Should You Choke a Generator?

To avoid excessive heat buildup and costly repairs down the road, a generator shouldn’t be operated on a choke for more than 1 – 2 minutes.

Does Choke Cut off Air?

Yes, the purpose of the choke is to block or unblock the flow of air to the combustion chamber; however, it should be utilized properly to avoid costly repairs down the road.

Does a Choke Add More Fuel?

Yes, if you turn on the choke the intake of fuel becomes high compared to the Choke at the OFF position.

Does a Generator Need a Choke?

Like all internal combustion engines, the generators also need a choke for a quick startup, especially if it is extremely cold outside.

Generator Choke on or Off

Depending on the situation if the engine is cool, you have to ON/Close the choke for an instant startup, however, if the engine is warm you should keep the choke OFF/Open position for better runtime, output, and cooling process.



Kashif has been a valuable asset to the electric generator industry for over 5 years. Now, As a skilled energy engineer, he’s been on the front lines of diagnosing problems, fixing broken parts, and performing routine maintenance tasks to keep generators running smoothly.

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