a damaged or malfunctioning diaphragm can lead to improper fuel delivery. If the diaphragm cannot maintain pressure, air can enter the fuel line.
Sticking or Malfunctioning Pump Valves: The fuel pump typically consists of inlet and outlet valves. If these valves are stuck or not sealing properly (due to dirt, wear, or damage), it can cause a disruption in fuel flow, leading to the formation of air bubbles in the fuel line.
Blockages in the Carburetor: Any debris or buildup in the carburetor can restrict fuel flow. This can create a vacuum that pulls air into the fuel line, particularly if the fuel mixture has to work harder to get through a blockage.
If the gasket between the carburetor and the engine is damaged or not sealing properly, this can allow air to leak into the fuel system, causing bubbles in the line.
Improper Carburetor Settings: If the carburetor is out of adjustment (wrong air-to-fuel mixture), it can affect fuel delivery and might lead to air being drawn into the system.
Cheers
Max.
