What is the purpose of an automatic choke when starting a cold engine?
In cold weather, the engine requires more fuel than air to start properly. The choke mechanism blocks some of the incoming air from entering the carburetor. As the engine warms up, it is able to operate with more air and less fuel, so the choke is no longer needed. Early gasoline engines used a manual choke mechanism.
What does an automatic choke do?
Automatically – An automatic choke uses a metal spring to open and close the choke plate. The spring is wound in a housing and attached to the choke linkage on one end. As the engine warms up, it warms the metal spring. As the spring warms, it expands, rotates, and opens the choke plate.
Where does the choke go on a cold engine?
When cold, the little screw at the top of the throttle arm should now rest on the top step of the stepped cam. This sets the hi-idle, which is needed together with the choke on a cold engine to provide sufficient idle speed to keep the engine running until it warms up fully.
How can I tell if my car choke is bad?
What we usually see with a bad auto-choke is that the engine will start up and run great cold, but as the engine warms up there will be problems driving, starting, and/or idling. Remove choke assembly from the choke holder on the side of the carburetor. The needle should be clearly visible.
How does the automatic choke work on a car?
As the engine warms up, the coil voltage heats an element inside the automatic choke, causing a bi-metal spring to uncoil, opening the butterfly valve, and moves the cam to reduce the idle speed. Release the throttle arm so that the return spring snaps it back.
How to adjust the automatic choke on an aircooled engine?
When this valve is closed the flow of air is very much reduced and the fuel/air mixture is rich. When the valve is open the flow of air is maximized and the fuel/air mixture should be correct for a warm engine.. The engine must be cold to make this adjustment. Remove the air cleaner. Find the automatic choke.
Why do I need to auto choke my lawn mower?
Hence, lawn mower users should consider automating the choke process on any engine start-up to ease the potentially challenging situation. Autochoke Process. A cold engine causes the internal spring to exert a consistent pressure on the engine choke control to ensure a closure on the choke plate.
How do you test an automatic choke on a scooter?
Either the choke unit itself is faulty, or there is a problem with the power supply to it. If you have a multimeter you can test the power supply by disconnecting the automatic choke and touching the meter leads onto the wires which the choke was connected to whilst running the engine at a fast tickover – (make sure not to touch them together!)
How do you remove choke from moped engine?
Switch off the engine and *quickly* remove the moped choke unit. You need to do this ideally within 30-60 seconds max of switching off the engine, so make sure you’ve already removed any panels beforehand which are in the way. To remove it just under the 2 screws holding in the horseshoe ‘U’ clip and pull it out.
How does choke work on iboats boat engine?
When engaged, they restrict the flow of air through the carburetor forcing more fuel to be drawn through the idle and mid-range jets while cranking. The choke is only effective while the motor is turning and drawing air through the carburetor body. Place the throttle in the start position.