If you’ve bought your new lawn mower, you’ll need to engage the choke when starting or running the mower. But before that, you must understand what the choke symbol entails and how engaging the choke lever affects your mower. So, what is the symbol for choke in a lawnmower?
If you find choke symbols confusing, don’t worry. This article covers you. We’ll explain a lawnmower’s choke symbol, how to read it, and more. Let’s get started.
What Is a Choke Symbol?
The choke symbol in lawnmowers shows when the choke valve is open or closed. When the choke is closed or in the “On” position, it regulates airflow into the carburetor. This controls the air entering the cylinders to mix with the fuel.
In other words, when the choke is on, it “chokes” airflow into the carburetor. This helps to start the engine, especially in cold weather. With restricted airflow, more fuel goes to the engine cylinders to provide extra heat needed to start the engine.
A lawnmower choke has a metal plate attached to the choke lever. When you engage this metal plate in the “on” position, it rotates to cover the airflow. This allows a limited amount of air into the carburetor. Restricting airflow allows a perfect mix of fuel and air that can warm up the engine.
This practice is helpful when temperatures are low. Typically, lawnmowers struggle to start when the engine is cold. The available fuel doesn’t maintain the optimum temperatures needed to start the engine.
On the other hand, an open or “Off” choke symbol allows air to flow freely. When you engage the symbol for choke off, the airflow becomes “unchoked” and flows freely into the cylinders to mix with the fuel. This happens when the engine has been warmed up enough to be operated.
How To Read Choke Symbols
You now know what the symbol for choke in lawnmowers means. But how can you tell what each symbol indicates?
Before we answer this question, it’s worth noting that mower models can have varying choke symbols. So, it’s necessary to understand what choke symbols in your mower indicate. Below we look into different choke symbols and what they mean.
An “O” Symbol With a Line
Some mowers have a horizontal or diagonal and vertical line running across the “O” symbol. An “O” symbol with a horizontal or diagonal line in the center indicates the choke is in the “On” position. Pull the choke lever up or forward to point to the choke closed symbol.
On the other hand, an “O” symbol with a vertical line in the center indicates the choke is in the “Off” position. You can pull the choke lever down or backward to point to the symbol for choke open.
A Rabbit and a Turtle Pair
This is another common symbol for choke you’ll find in lawnmowers. The rabbit symbol indicates the choke is open to allow airflow. This means the engine is ready for operations.
The turtle symbol indicates the choke is closed to regulate airflow. This allows for a steady flow of fuel into the engine to allow it to start.
“I” and “O” Choke Symbol
Some mowers feature “I” and “O” choke symbols with a red or blue switch. These symbols appear on the alternate sides of the red or blue switch.
The “I” position indicates the choke is on or closed to restrict airflow. You can press the switch to the “I” position to start the engine when the temperatures are low.
The “O” position means the choke is off or open to allow air to flow freely. Press the switch to the “O” position when the engine has warmed up and is ready to be operated.
Some mower models don’t feature the above symbols. They may feature choke controls with the following labels:
- Open/Close: The “Open” label means the choke is off, while the “Close” label indicates the choke is on.
- On/Off: The “On” label indicates a closed choke, while the “Off” label means the choke is open.
- Start/Closed: The “Start” label means the choke is on, while the “Closed” label indicates the choke is off.
- Full Choke/Run: A “Full Choke” label indicates the choke is on or closed to allow air to flow. Sometimes, “Full Choke” can be labeled as “Choke.” The word “Run” indicates the choke is off or open.
Mowers with twin-cylinder engines might have a “Half Choke” label between the “Full Choke” and “Run” labels. The “Half Choke” indicates the choke is halfway opened or closed. This choke control prevents the mower from dying out when switching from the “Run” to the “Full Choke” position.
You’ll need to switch to the “Half Choke” position to allow the mower to adjust to the restricted airflow. Once the engine adjusts, you can switch the lever to “Full Choke” without causing the engine to knock off.
What if your mower doesn’t feature the “Half Choke” label? Set the choke lever between the “Full Choke” and “Run” positions to prevent your mower from dying out. Once the lever is in the middle, your mower will adjust to the reduced airflow.
If understanding the symbol for choke sounds confusing, refer to the owner’s manual. You’re sure to find information about the meaning of each choke symbol and the ideal position to move the choke lever when starting or operating the mower.
Location of the Choke on Lawn Mowers
The position of the choke varies from one lawnmower to another. This is especially true for different models or mowers from different manufacturers. However, most mowers have a choke valve located on the engine body. Others have a choke lever positioned on the mower’s handle.
With time, you’ll find it challenging to locate the choke on your lawn mower when it gets covered by dirt and debris. Thankfully, some mowers feature a bulb on the choke symbols. If the bulb malfunctions, you won’t be able to tell whether the choke is in the on or off position.
If your lawnmower features a butterfly valve, you’ll find the choke in the manifold.
When locating the lawnmower choke, it’s necessary to consider whether you have a manual or automatic choke. You can locate a manual choke by following the cable linking the trigger to the engine. For an automatic choke, find it near the air intake, just next to the carburetor.
Can You Operate a Lawnmower With the Choke On?
It’s wrong to run your lawnmower when the choke is on. The choke is helpful when starting your mower to optimize fuel combustion. Switching the choke to the “On” position creates a low air-fuel ratio, producing a rich fuel mixture.
When the fuel runs rich, it contains less air and gets easy to heat up. Heating fuel to operating temperatures provides the required power to start the engine.
After starting the engine, switch the choke to the “Off” position. Failure to do this can cause more fuel to continue burning rich. Eventually, your engine uses more gas and might develop overheating problems. Other issues you may experience include:
- A leaking carburetor
- Damage to engine components
- Decreased power
- Increased pollution
If you open the choke when starting the engine, you may experience various starting problems. Allowing too much air into the carburetor and combustion chamber cools down the engine. If you try to start the engine, it may sputter, stall or shut down.
The goal is to ensure the combustion engine receives the right amount of air. To achieve this, understand when to turn the lever to match the correct symbol for choke.
Once the engine starts, open the choke to allow a steady airflow. Doing this creates a high air-fuel ratio known as a lean mixture. Your lawnmower engine requires lean fuel to keep running smoothly. This is a great way to use fuel economically, maintain the engine in top condition and reduce pollution.
When Should You Run the Lawnmower With the Choke On?
After starting the engine, you may opt to run your mower when the choke is on due to the following reasons:
- When there’s a blockage in the fuel line or fuel filter – Blockage can prevent enough fuel from reaching the carburetor.
- When the octane mixture in the fuel is less than optimal – This usually happens if there’s water or additives in the fuel.
Fix these issues first before operating your mower. You can do this by unblocking the fuel line and replacing the filter. If the culprit is the fuel mixture, drain it and add fresh fuel.
Should You Leave the Choke on During Storage?
When storing your mower, turn the choke to the “Off” position. When warming the engine for start-up, you only need to move the choke lever to the “On” position.
Turning the choke lever to the “Off” position makes your work easier the next time you want to operate your mower. You don’t have to refer to the manual to know if the choke is opened or closed.
If you want to start the engine, especially when the weather is cold, you only need to switch the choke lever to the “On” position.
When using a lawnmower, it’s advisable to understand the symbol for choke to ensure smooth operations. Choke symbols vary from machine to machine.
A closed symbol indicates the choke is on to regulate airflow into the carburetor and combustion chamber. This practice is beneficial when turning the engine on.
An opened symbol indicates the choke is off to allow air to flow freely. After warming up the engine, you can turn off the choke to run your mower.
Hello! My name is Chris, and I am the founder of Yard Floor. When I was a toddler, my family had a lush green lawn. I was at the center of caring for and maintaining this lawn and even proceeded to take an associate’s Degree in landscaping. I am here to share my years of experience with you – be it repairing your mower/tractor or caring for your lawn.