What Choke Does On a Generator

Generators are an integral part of any power system. Like most machinery, they are not immune to failure. If a generator experiences a malfunction or fails to start, it can disrupt the flow of electric power.

That said, there are numerous reasons why a generator may not start. However, one of the most common causes is the choke. So, what does it do on a generator?

The choke on the generator functions as an air-control mechanism. It restricts airflow into an engine through the pistons which provides for ideal fuel-to-air ratios for combustion. Basically, without a choke, your generator’s engine will stall due to excess fuel in its cylinders.

Although a minor problem, it can quickly escalate into something more severe without professional attention. Understanding what causes choking and how to fix it will help prevent potentially dangerous situations in the future.

What Does a Choke Do On an Engine

Before we get into how a choke works, let’s discuss what it does on an engine.

The choke acts as an automatic switching valve that regulates fuel supply to an engine. It does so by opening and closing a port inside your generator that allows additional fuel to flow in when needed and blocks it when not.

How Choke Works

What Choke Does On a GeneratorBy adjusting your choke, you control how much air gets into your engine. All generators come with choke controls, so let’s look at what they do and how to use them.

An engine requires fuel to run. And with fuel comes air, which is needed for combustion and allows pistons to compress and expand under pressure in an internal combustion engine.

However, engines need just the right amount of oxygen to run correctly. Too little oxygen and they won’t ignite; too much could destroy them.

That is where choke comes in handy. Airflow increases when you pull up on a choke and decreases when you push it down. For instance, if you want to run richer (more fuel), pull up on your choke; push down on your choke control if you want to run leaner.

Slowly open up your choke

once the engine has stabilized its idle speed until you reach operating temperatures. Once those operating temperatures are achieved, slowly close off your choke control slightly at a time until you return to optimal idle conditions while maintaining optimum coolant temperature.

Turning in direction one way will lean out the air/fuel mixture, and turning in direction two will enrich the air/fuel mixture.

So, if you find yourself having trouble starting your generator, or it sounds rough when running, you may want to check out how much choke is applied and adjust accordingly.

Choke Position on a Generator

What Choke Does On a GeneratorThe first step is to identify your choke. Firstly, on all chokes, you will see an ON/OFF label which allows you to know whether or not your choke is open or closed.

Secondly, note that most chokes have handles directly or alongside. The handle allows you to manipulate and open and close your choke.

Choke levers are generally located on the side of generators right above the air filter. Others have theirs built-in or close to the power control knob.

So, where should the generator’s choke be positioned?

To get optimal performance from your generator, you will want to know the positions of your choke when the engine is cold and when it’s hot.

When the engine is hot, you should have your choke lever opened all the way. Conversely, when the engine is cold, you’ll want to close off your choke but not all the way. By closing off partially, you’re allowing more time for fuel to be introduced into the carburetor so that it can get ignited without problems.

Should the Choke Be Open or Closed On a Generator

If you’re having trouble starting your generator, or if it dies every time it goes into standby mode, it might be time to check your choke and ensure it is appropriately set for your generator.

So here’s the question: should a choke be open or closed on your generator?

To start a cold engine of your generator, you’ll want to close your choke. This restricts airflow, which increases compression and provides for easier ignition. However, once the engine fires up and begins to run smoothly, open your choke until it settles into its average operating speed.

How to Start a Generator with a Choke

Starting your generator with a choke is less daunting and more efficient with the correct information and preparation. Below are the steps to start your generator with choke quickly and easily.

1st Step: Move Your Generator Outdoor

Don’t run your generator in an enclosed area like a room or garage; you risk carbon monoxide poisoning. Instead, take it outside and point it away from your home, preferably downwind.

To prevent electrical fires, don’t plug extension cords into each other. Ensure they are UL-approved for outdoor use. Also, don’t get too close: generators can kill if they spark up within 3 feet of you and cause injury from falling debris.

2nd Step: Refuel Your Generator with Fresh Fuel

Before starting your generator, you should ensure that it has enough fuel. Many generators are equipped with an indicator light to know when your tank is low or empty.

3rd Step: Check for Oil Level

What Choke Does On a GeneratorEnsure you have enough oil in your engine. If not, add more before you start. Check your owner’s manual for guidelines if you’re unsure about how much to put in.

4th Step: Turn Fuel Valve On

Locate your fuel valve. You will see a black or yellow knob marked fuel on it. It is typically on one of your generator’s sides and not inside its main compartment. Turning that knob to its position allows fuel into your generator.

5th Step: Pull the Choke Lever On

The choke lever is located at the front of your generator, right above the air filter. You want to pull it out and give it a little twist. Sometimes, an arrow next to it indicates which direction you should rotate. You may also see some text that says “Pull Out” or “Push-In.”

6th step: Press Engine Control Switch / Pull the Recoil Cord to Run

Start your generator. If it’s battery-powered, start it by pressing an Engine Control Switch. However, pull that instead if you have a recoil cord starter engine.

7th Step: Gradually Push the Choke Lever to Off

After starting your engine for several minutes, push the choke lever to the off position. The engine should be warm and running smoothly at that point, so all you have to do is let it run on its own.

8th Step: Plug in the Power Cord

What Choke Does On a GeneratorOnce your generator has run for a while and is warmed up, you’re ready to plug in your electric power cord and finally power your appliances.

Generator Choke Problems and How to Fix

Few things are more frustrating than having your generator choke out on you when you need it most. However, if you’re careful and attentive, you can avoid a significant number of common generator choke problems.

Read on for five of these issues, plus tips on fixing them before they happen.

1. Broken or Worn Out Choke Lever

The choke lever helps you control how much fuel goes into your generator, which is extremely important for running effectively.

A broken or worn-out choke lever can cause all sorts of problems such as not turning on and off, variable running speed, shutting off during use, etc. If your generator choke lever is broken or severely worn out, you’ll have to replace it.

2. When the Choke Is Turned Off, the Generator Dies

Your fuel to air ratio is out of whack if your generator dies every time you turn the choke off. To fix it, turn the choke back on, then open the fuel flow a little bit until the engine runs smoothly with all air coming in through the air filter.

Once you reach that point, close the fuel flow back down to match your usage. It might take some time for adjustment, but once you get it right, your fuel will last much longer than before.

3. The Generator Only Run If the Choke Is Turned On

If your generator only operates when the choke is turned on, you most likely have a faulty engine diaphragm. The condition may result in increased fuel usage.

This problem could be as simple as replacing the choke cable or as complicated as replacing your engine diaphragm. For more information, contact an expert or your generator manufacturer.

4. The Generator Operate Only On Half Choke

If your generator only runs on half choke, it means inadequate fuel flow, especially for larger generators.

You can do a few things to fix this: Check that your tank is full of gas; ensure your fuel line isn’t clogged. If none of these solutions work, you may have a faulty carburetor. All you have to do is replace it or take it in for service.

5. The Generator Only Run If the Choke Is Set To Full

Some engine choke problems are easy to spot, like when a generator only runs on full choke. This is likely because of an airflow problem that gets easily solved with a simple adjustment or cleaning of your carburetor.

Alternatively, it may be caused by worn-out gaskets in your carburetor, which can cause air leaks. In either case, you’ll need to replace parts for your generator to work optimally.

6. Without A Choke, the Generator Will Not Run

Most small gas-powered generators come with a choke system. The purpose of a choke is to increase airflow into your generator.

If you own a generator that won’t run without using its choke, you probably have a clogged carburetor, dirty air filter, or simply the choke can’t close/open all the way because it’s broken.

Before you try anything else, make sure there isn’t any debris in your fuel tank. This means removing old gasoline then running fresh fuel through before starting it again.

Faqs Regarding Generator Choke

1. Can a generator run on choke?

No, an engine cannot run without air being drawn in and mixed with fuel for combustion. Chokes are to regulate airflow into an engine. If you over-choke it, not enough air enters. Additionally, over-choking causes incomplete combustion and poor performance.

2. Why is it so hard to pull-start my generator?

Your choke could be set too high. This means that it restricts airflow into your generator. If you have enough gas and everything else is in order, you may need to adjust your choke setting.

3. What happens if you run an engine with the choke on?

Running an engine with the choke on can lead to several problems, including poor performance and excessive fuel usage. A chocked engine will be under-fuelled, meaning it runs at low RPMs while simultaneously burning lots of gas.

Ultimately, running your engine with its choke on could cause overheating, thus damaging its internal systems or burning out its motor entirely.

4. How do you fix a generator that only runs on choke?

If your generator is only running on choke, you may have an issue with your carburetor. The choke could be closed and restrict airflow. Or, it could be out of adjustment and not fully open when turned off.

To fix these issues, remove the air filter cover and make sure there isn’t any debris blocking airflow.

5. Why does my Briggs and Stratton engine only run-on choke?

To put it simply, their engines are designed to run at two speeds: idle and full throttle. At idle speed, the engine needs enough fuel to keep it running.

However, if you want more power from your motor, you need more air for combustion inside the cylinder head. So on Briggs and Stratton engine, a choke helps move extra air into that cylinder.

6. What happens if you leave the choke on too long?

If you leave your choke on too long, you risk stressing your engine. This leads to overheating or severe damage in some instances.

Many models will automatically shut off after a certain period if they sense that they are not receiving sufficient air; others make an odd noise or begin to vibrate.

7. Does a choke add more fuel?

The choke will increase fuel because the engine’s throttle is closed or partially closed. The air that has already entered through all of your intake system inlets must pass through your carburetor, which then mixes with more fuel from your gas tank before it enters into your combustion chamber.

8. How long do you leave choke on?

Well, that all depends, how cold is it out? You will want to leave the choke if it’s cold out until you get things warmed up well. If it’s just springtime, then you might want to turn it off and wait till everything is warm before turning it back on.

Bottom Line

The choke is an important safety feature of your generator. Its primary function is to keep the engine from stalling.

In the absence of the choke, an engine can die from excessively lean mixtures. It would leave you without power if you were trying to run critical devices at home or in your business.

Today, most engines are equipped with automatic chokes. That means you’ll never have to turn the choke on or off while doing your job. Even so, knowing how it works will assist you in determining how to repair your engine if it stalls.

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About Steve Stuart

Steve Stuart is an electrical engineer who developed interest on generators during his school years. After school, he became a generator enthusiast. This is after encountering power supply problems at the area of residence where he lived. Power would be on and off and so food would go bad and the room heater would go off especially during winter. After trying the different generator brands for several years, Steve now provides information on the available brands and products in the market today. Based on his experience, he gives the do’s and the don’ts when it comes to generator use.

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