CITROEN 2 CV4 1975 Owner's Manual page 43

Fig. 47
Electrode gap
MINOR REPAIRS
Replacing a sparking plug
FACTORY FITTED:
AC 42 F
BOSCH W 225 T1
EYQUEM 755
MARCHAL 35
CHAMPION L 85
MARELLI CW 7 N BT
Electrode gap: .026" to .030" (0.65 to 0.75 mm) (Fig. 47).
Removal:
After starting to undo the sparking plug with a plug spanner
(wrench), push a rubber tube over the insulator to ease removal.
Finish undoing the plug then take it out.
Fitting:
Cap the insulator of the replacement plug with the rubber tube.
Screw in the plug with its tube until finger tight.
Finish tightening with the plug spanner (wrench).