How to use a Choke: Mastering the Choke Function in Small Engine Operation

You might have come across something called a choke when trying to start your small engine equipment and wondered if you're using it correctly. The good news is that whether you're starting a lawn mower, snow thrower, pressure washer, or any small engine machine, the process is the same! This article will help you better understand how to use the choke so you can start your small engine equipment effortlessly!

If you're unsure what a choke is, don't worry. It's best to think of it as a door or plate. Engines essentially function as air pumps, and a choke is used to create a vacuum that draws a fuel and air mixture into the engine's cylinder to be ignited by a spark plug.

When the choke plate is in the closed position (though it is actually slightly open to allow some air to pass through), pulling the starter rope causes the piston to move down in the cylinder, creating a vacuum due to high and low pressures within the cylinder and the surrounding air.

Why is this important? Because if the choke plate is open when you try to start a small engine, there won't be enough vacuum to draw the air and fuel mixture into the engine, preventing it from starting. There would be no high and low pressure areas between the surrounding air and the air inside the cylinder.

This machine's choke is not operator controlled; it is an autochoke but functions exactly the same way as if it were operator controlled

Pro tip: Remember to keep the choke plate closed when starting a cold engine! Open the choke once the engine has started and run for a short while (depending on temperature and application).

Another important point is that the symbol on your machine's choke lever may resemble an open and closed door, making it easier for the operator to distinguish between the open and closed positions.

To start a small engine that is mechanically sound, begin by finding the choke lever. This lever is typically located on the intake side near the carburetor or on a separate handle labeled "choke." It will have multiple positions to choose from, often marked with symbols for "open" and "closed," resembling a plate or door. Set the choke to "closed" to start the engine, and then switch it to "open" once the engine has started and warmed up.

And there you have it, now you know how to use a choke!

Choke plate in closed position; can still allow air in to create a vacuum in the engine (from looking into the throat of the carburetor)

Choke plate open: once engine started move to this position to maintain air flow and keep engine running! (from looking into the throat of the carburetor)

Never the Norm!