I have a mostly stock 72 240,( for now) I just gave it a tune up from hibernation. New wires7mm, rotor & cap, Bosch platinum plugs gapped @ 33, and a bench rebuild of the SU's. Ran like a Monster for a week & now only 3's fouling out. All the plugs are burning fine (lil' rich) but 3 comes out cold & wet.
I check it on the valve cover & good spark. but it only stays for about 2 min. No power, Slightly irratic idle, and stuttering.
Any reccomendations ?

do it Munkystyle !

 

had similar trouble. changed coil and went fine. could be it. hope. try a second hand one from another car like a mates one and see iff changes