Fouled #1 plug

[indyman13]

I know these old log head engines are notorius for poor intake flow. My 200 is pretty stock with the exception of a 2bbl added to the stock manifold (with stovebolt adapter) and Pertronix ignition and coil. It was running rough today and #1 plug was completely fouled. There was black crud bridging the entire space between the side and center electrode.

Cleaned it up and it's back to running just like always (0 to 60 by lunchtime)

Plugs are gapped at .045-----timing is set at 10 BTDC------premium fuel----head rebuilt 15K miles ago with hardened seats.

Suggestions or insights?

 

[az1966]

only thing I can think of and I'm no pro to be sure is a cracked block or head.,,,reason being I've got the same thing and the cylinder is cracked

 

[CZLN6]

Howdy Back:

And Merry Christmas. From you description my first guess is that it is oil fouling. And since it is only on the #1 my guess would be 1, a weak/dead spark plug, wire or connection, 2, the valve stem seal is gone, or 3, a broken ring or cracked piston. I'd start by replacing the spark plug, check the plug wire and connections. If that doesn't do it, I'd pull off the valve cover to visually inspect the valve stem seals. If a seal is off, broken or just plain gone, I'd replace all seals. I'm assuming that the seals were replace when the read was rebuilt????? If the problem is not 1 or 2, then you'll have to be looking deeper.

You didn't say which carb you are running with the Stovebolt adapter, but I'm guessing a H/W 5200. If it is running good, I doubt that it or "poor intake flow" are the problem. Also, what trans is in the car? Did you check all the spark plugs?

Adios, David

 

[fordconvert]

New cap, rotor, plugs, and wires. If all that stuff is new then do some swapping to see if the problem moves. Hate to tear into the motor for something dumb like a bad wire.

 

[indyman13]

I'll take all the plugs out this weekend and have a look. Probably a good idea to do that on a kind of regular basis anyway. I'm thinking bad plug wire connector because it's sure easy to take that number one wire off the spark plug. Almost like it's not clamping itself to the connector real good and lots of "slop".

 

[Broncitis]

All I do is diagnose appliances all day long for myself and others and the one thing I have learned is always start with simple no matter what someone else says.

 

[BIGREDRASA]

All I do is diagnose appliances all day long for myself and others and the one thing I have learned is always start with simple no matter what someone else says.

+1

In addition, if you have to start replacing parts, start with the least expensive.

 

[jahearne]

I'll take all the plugs out this weekend and have a look. Probably a good idea to do that on a kind of regular basis anyway. I'm thinking bad plug wire connector because it's sure easy to take that number one wire off the spark plug. Almost like it's not clamping itself to the connector real good and lots of "slop".

I thought you did that already and was thinking why only one plug was fouled - bad wire, plug or excessive oil consumption on no. 1. If all plugs are fouled black are they sooty or oily? If sooty black then you have a carb that's running too rich.

I recently found nearly all my plugs fouled where the plugs gaps were bridged with white/brownish crud. I advanced the timing to the point of pinging then backed off a bit. That seemed to do the trick. If that did not work I was going to go with hotter plugs.

Good luck,

 

[CobraSix]

I agree...check the simple things first.

Replace the wires if they are old. New Cap and Rotor would be a good idea as well along with a new plug.

 

[69.5Mav]

Any Progrss?