Tech Tip – Automatic Choke and Coolant Level

From Moss Motoring 1985

Too Little Too Fast

When servicing late model MGBs fitted with automatic choke, pay special attention to the coolant level. If the coolant level is too low, there will be insufficient flow through the automatic choke causing extremely high idle speed.

To Refill the Cooling System:

1. Fill the expansion tank half full and replace the cap.

2. Fill the system through the filler plug hole in the thermostat housing and replace the plug.

3. Run the engine until the top hose is warm to the touch. Shut off and allow the system to cool.

4. Refill the expansion tank to half full, replace the cap.

5. Top up the radiator through the filler plug and replace the cap.

Auto chokes fitted to Zenith carburettors have proven unreliable and expensive to service. Moss Motors manual choke conversion kit (#386-320) is easily fitted to the existing assembly and allows you control of the choke.

John Richard Salisbury, CT




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