I have tried to resolve this problem but no luck. Last option, plug leads and distributer cap. Plug leads had pin pricks where spark shorted. See picture of cap, Problem solved.
I have tried to resolve this problem but no luck. Last option, plug leads and distributer cap. Plug leads had pin pricks where spark shorted. See picture of cap, Problem solved.
Sometimes caused by plug lead not pushed all the way in followed by the rubber cap so the spark jumps the gap to the contact in damp weather etc. in the past. Or a break in the carbon leads which again causes spark to take the easiest route.