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so I installed some new plugs and after 100 miles I took them out to look at them and cylinder 8 plug looks black and the rest look normal could this be just running to rich are an j looking at worn piston rings ? Any help would be awesome
Cylinder 8
Are all five of your photos the same plug? The last photo looks cleaner. Is that after you cleaned it up? It would be nice if the photos were in better focus. Instead of holding the plug in your hand, put it down on a flat surface and get the camera to focus on the tip.
The chart below should help. I would say that the top two photos look most like the fourth image down on the left side on this chart, but because of the focus problem, it's hard to tell if the deposit on your plug is wet or dry. That does say worn piston rings could be a cause.
Well I just noticed I was missing a nut on my valve cover right by cylinder 8 plug also I did compresion test and I have 155 on all cylinders the plug is black and kind of wet with oil hoping the missing but was the problem
First off, those plugs don't work very well in these old engines. Buy some standard plugs. The one plug may be burning black due to a weak spark, possibly bad plug or wire. It also could be a bad valve guide seal, or other reason oil may be getting in to that cylinder.
You should be looking for probably one thing on one cylinder #8. Carb adjustments would effect all cylinders. I would suspect either a bad wire, bad plug or something on that particular cylinder. A missing bolt on the valve cover would not foul a plug. Does it smoke on startup? What does the distributor cap look like, any cracks or is it hei.?.... Tedd
I had oil in cylinder 8 I tightened down valve cover and just haven’t been able to run it to see if that fixed it I was thinking that oil got in there from valve cover not being sealed ,a little smoke on start up if I hold down accelrater but if I just crank it up no smoke distributor is PerTronix D186504 Flame-Thrower Electronic Distributor
No way could oil get into a cylinder from a leaky valve cover. It could get around the plug wire or plug sleeve and maybe short it out or something like that but no oil will ever make it down the hole through the spark plug . I would double check your distributor cap and wires or it could be a bad valve seal as mentioned above.... Tedd
