strange spark problem - anybody have ideas?

[daddiodanger]

from time to time cylinder six stops firing. usually i pull the plugs and clean them off or replace them. i am aware that the carbs need to be overhauled and what not, but i don't think that is my problem.

however, one day i pulled the boot off of the plug and the cylinder fired then cut out. i put the boot back on and the cylinder fired then stopped.

so i was thinking the plug wire was bad so i tried a different one, and the same thing happened. so i pulled the plug and replaced it. and it was fine for three days then it happened again. so i've been driving around with the plug wire half way off. and it been fine.

it seems extremely odd.

i'm wondering if there is something goofy with the distributor?

[Arne]

No, it sounds to me as if your number 6 plug is fouling badly. When you pull the plug wire while the engine is running, you make the spark jump from the wire to the plug, which in effect makes the spark hotter. Running with the plug wire partway off is an old shade-tree mechanic trick to reduce plug fouling from way back. So I think your problem is either carburation (way rich on the rear carb), or more likely (since it is only the number 6 plug that fouls) collapsed or sticky oil rings in number 6.

[Doehring]

No. 6 cylinder is very heat sensitive. I hope you don't have a problem with the cylinder head gasket. A compression test might give you clearness.

Rolf

[daddiodanger]

cool , good info thanks

this is a new one for me.

this is my first carburated car so i'm learning alot.

i have had issues with the carbs and the motor does need a new head gasket.

i have another motor that i am putting together.