Morris Minor Owners Club

you do need to set the idle a little quicker than seems normal, to allow for the extra resistance the operation of the clutch applies.

it should only slow the engine a little, if it's ticking over quite fast and still the engine still dies when you depress the clutch then it could be that, as suggested, the clutch is travelling too far. i'm not sure of the recommended amount of free play but it is covered in 'Matt Tomkins' recent thread about clutch adjustment.

found it:

Turn the nuts clockwise to decrease free play, which is what you need to do. 1.25 ins for 1098, 3/4 for 948, measured at the top of the pedal.