How to check the choke on a carbureted engine
Auto repair

How to check the choke on a carbureted engine

09.11.2022 /

The throttle valve is a plate in the carburetor that opens and closes to allow more or less air into the engine. Like a butterfly valve, the throttle valve rotates from a horizontal position to a vertical position, opening a passage and allowing…

The throttle valve is a plate in the carburetor that opens and closes to allow more or less air into the engine. Like a throttle valve, the throttle valve rotates from a horizontal to a vertical position, opening up a passage and allowing more air to pass through. The choke valve is located in front of the throttle valve and controls the total amount of air entering the engine.

The throttle is used only when starting a cold engine. During a cold start, the choke must be closed to limit the amount of incoming air. This increases the amount of fuel in the cylinder and helps keep the engine running while it tries to warm up. As the engine warms up, a temperature-sensing spring slowly opens the choke, allowing the engine to breathe fully.

If you are having trouble starting your car in the morning, check the choke on the engine. It may not close completely on cold start, allowing too much air into the cylinder, which in turn prevents the vehicle from idling properly. If the choke does not open fully after the vehicle has warmed up, restricting the air supply may result in reduced power.

Part 1 of 1: Inspect the Throttle

Necessary materials

  • Carburetor cleaner
  • rags
  • Safety glasses

Step 1: Wait until morning to check the choke.. Check the choke and make sure it is closed when the engine is cold.

Step 2: Remove the air filter. Locate and remove the engine air filter and housing to gain access to the carburetor.

This may require the use of hand tools, however in many cases the air filter and housing are attached with just a wing nut, which can often be removed without the use of any tools.

Step 3: Check the throttle. The throttle body will be the first throttle body you will see when removing the air filter. This valve must be closed because the engine is cold.

Step 4: Press the gas pedal several times.. Press the gas pedal several times to close the valve.

If your car has a manual choke, have someone move the lever back and forth while you watch the throttle move and close.

Step 5. Try to slightly move the valve with your fingers.. If the valve refuses to open or close, it may be stuck closed in some way, either due to a buildup of dirt or a malfunctioning temperature controller.

Step 6: Use Carburetor Cleaner. Spray a little carburetor cleaner on the choke and then wipe it with a rag to clear any dirt.

Cleaning agent can safely get inside the engine, so don't worry about wiping down every last drop of cleaning agent.

Once you close the choke, install the air filter and housing onto the carburetor.

Step 7: Run the engine until it warms up. Turn on your vehicle's ignition. When the engine is warm, you can remove the air filter and check if the choke is open or closed. At this point, the choke must be open to allow the engine to breathe fully.

  • A warning: Never start or accelerate the engine with the air cleaner removed in case of fire back.

When you inspect the choke, you also have the opportunity to look inside the carburetor. If it is dirty, you may want to consider cleaning the entire assembly to keep the engine running smoothly.

If you are having trouble identifying the cause of an engine problem, have an AvtoTachki certified technician check your engine and determine the cause of the problem.

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