plug fouling

Posted By: MoparJunkie

plug fouling - 09/25/11 01:22 AM

Hey guys I have a 505" six pack motor... took it on a long run today... 120 miles, and now cyl's 1 & 4 have rich fouled plugs(black soot). All the other cyl's plugs are tannish brown color... What gives??? How can just those two plugs foul like that?

Posted By: MR_P_BODY

Re: plug fouling - 09/25/11 01:36 AM

3 things come to mind... too cold of plugs... too fat
on the fuel and a poorly flowing intake(the runners
arent balanced)

Posted By: MoparJunkie

Re: plug fouling - 09/25/11 01:41 AM

If I was too fat on the fuel wouldn't I have more than 2 fouled plugs????? I can understand the runner issue??? I am running a NGK BKR6E plug...

Posted By: rickraw

Re: plug fouling - 09/25/11 02:08 AM

i'd do a leak down test on those clyinders. check ur valve adjustment also. stay safe, seeya.

Posted By: MR_P_BODY

Re: plug fouling - 09/25/11 02:10 AM

Quote:

If I was too fat on the fuel wouldn't I have more than 2 fouled plugs????? I can understand the runner issue??? I am running a NGK BKR6E plug...

Since all of them are a tad fat(tan color) you could
jet down or put in a hotter plug... or put in a hotter
plug in those 2 cyl(it will work but not my first
choice)

Posted By: sixpackgut

Re: plug fouling - 09/25/11 02:42 AM

Quote:

If I was too fat on the fuel wouldn't I have more than 2 fouled plugs????? I can understand the runner issue??? I am running a NGK BKR6E plug...

i dont know if you have stock carbs or metering plates that take jets, but from the factory the carbs are stagger jetted. you have a deep plenum and a short plenum. not sure on this but one plenum feeds 1467 and the other 2358. i jetted my carbs till they all looked the same.

besides, i still dont think that is the issue

Posted By: MR_P_BODY

Re: plug fouling - 09/25/11 02:53 AM

Quote:

If I was too fat on the fuel wouldn't I have more than 2 fouled plugs????? I can understand the runner issue??? I am running a NGK BKR6E plug...

Have you checked your plug wires lately... you could
have a couple going bad