MG Car Repair: Mgb 74

Question
What is the proper float level for my 74 mgb su hif carbs.? Have read that float levels should be set one mm. Below carb body at low point on float. Does not seem to be correct, please help
Also when car is hot, it will not start? Any ideas? coil?

Answer
Hi Robin

You are correct that the float must be set with a 1mm clearance between a straight edge and the dip in the middle of the float.  However, you must set this clearance with the carburettor turned upside down.  The float will therefore sit 1mm ABOVE the carb body when fitted to the engine.

Most hot restart problems on the MGB are caused by excess heat in the engine compartment:

1) Check that the heat shield between engine and carburettors is complete and undamaged.

2) The fuel line runs underneath the heater.  There should be a small metal shield to protect it from the heat of the engine.

3) Check your engine timing.  If the ignition timing is retarded this will cause overheating.

4) If you still have a long rubber seal fitted to the rear edge of the engine compartment, remove it, cut it into 3 pieces and re-fit parts 1 and 3.  Throw the middle section away.  This will allow more hot air to exit the engine bay.

Please let me know how you get on.