M that fowls # 4 hole

[mattwillson]

Hi gang.. I have a M that keeps fuel fowling #4 spark plug, any ideas on how to get her to stop doing it..I'm running delco c87 plugs
 

[David G]

Fix the leak.
 

[old]

Sounds like you have a bad spark on that cylinder so yep the plug fouls or you have very poor compression on that one cylinder or a bad plug. I would switch to an auto lite plug equal to a D-21 champion
 

[BigTone]

you might have anti-freeze slowly dripping into the cylindar. We have a Super M on the farm that has a drip into the cylindar and about once a week it fowls the plug. What they do is switch around the plugs every couple days to keep it from fowling. Someday we will replace the head gasket. Not sure if thats whats going on with yours but its something to look at.
 

[rustred]

very first step is to check compression, then go from there.if you have a low cyl. there"s the problem. not all these guesses.
 

[gene bender]

Have you tried a new wire
 

[robgIN]

what does the plug look like, just black fuel fouled or is it oil fouled? Compression test first, then a cyl leakage test if you have access to tester. Need to find the root cause or will just be throwing parts at it. All the suggestions are valid, a little time diagnosing will save you time and money in the long run.
 

[mattwillson]

Hi fellas, the ole mare fuel fowls #4, she has 85psi comp across the board which is fine because i turbo'd her. 12 psi boost seems to be the max,it doesn't lose coolant or puke it out of the rad. I bought a set of 3116 autolites, we'll give them a whirl.I'm running solid core wires(which are new, and test fine). It doesn't use oil(never has since i've had it). I did build an electronic ignition for it, using mopar stuff('cause it works). Maybe I just have a bad plug, we'll see what happens with the new ones. One thing I did notice is, if I hold the boot about a half inch off the plug it will fire the hole...I should know the reason, but can't remember off hand why.
Thanks for your input, it's always helpful.