MFI-What Color Are Your Plugs?
 

Well the saga of the MFI continues on my 72 911E. I know I am close to having the mixture settings set up right on the MFI in that I have gone to having the plugs foul from being over rich from every 3 days to every 30 days. I'm going to make a 1-click adjustment to the mid range screw tonight based on the fact that the plugs tend to foul quicker when I do more highway driving than in town driving. My question for those with the knowledge is what is the lightest color I can expect to see on my plugs? I know the MFI always tends to run rich, but my plugs are still very black and sooty. I know I will never see a tan color, but will they always have the dry soot on them? One other question, I have been running the NGK BPR6ES plugs thru the winter, are these too hot to continue to use in the summer? In the winter anything colder just fouled out sooner. Right now I am running at about 195-200 degrees when fully warmed up on a 90 degree day. Thanks!

Kurt V
72 911E

My 2 cents. I have a 72 911. I use to foul plugs like you do. After messing with it for a while i got the plugs to look somewhat sooty, an off black.I asked my local mfi guru what i could do to stop fouling plugs. He recomended a Bosch plug that cost 4 bucks a piece. These have 3 electrodes. I no longer foul plugs. They are called Bosch super. The plug number that i use is W7dtc. The 7 indicates the heat of the plug. You can 6, 5 and 8 i think. It sounds like you might have other probs though. Buy these plugs and try them. I will not use another plug. The color accross the board is a nice brown. Sometimes they hit a little black, just depends on the kind of driving.
good luck