* Incorrect choke adjustment: When the engine is cold, the choke is engaged, which enriches the air/fuel mixture to aid starting. As the engine warms up, the choke should gradually disengage, allowing the mixture to become leaner. If the choke is not adjusted properly, it may stay engaged even after the engine has reached operating temperature, so making the mixture too rich. This can cause the engine to run poorly and stall.
* Faulty carburetor: The carburetor is responsible for mixing the air and fuel to correct ratio for combustion. If the carburetor is not functioning correctly, it may not be able to properly mix air and fuel, so causing a loss of power.
* Spark plugs not gapped correctly. If the spark plugs are not gapped correctly, the ignition timing may be incorrect. This can cause the engine to lose power and chug.
* Vacuum leaks: Vacuum leaks can cause the engine to run lean, which can lead to a loss of power and chugging.
* Fuel pump: If the fuel pump is not working properly, the engine may not be able to get the necessary amount of fuel to run smoothly.
* Distributor: The distributor houses the ignition points and is responsible for making sure the spark is distributed to the spark plugs in the correct order. If the distributor is faulty, it can cause the engine to lose power and chug.
* Fuel filter: A clogged fuel filter can restrict the flow of fuel to the engine, which can cause it to lose power and chug.
