Number one plug keeps fouling. numbers two and three look good, brown on the eletrode. number four is more black but one is maybe oil fouled. Could this be a bad valve or stuck oil ring. And if you can tell without taking the head off.

Are you running a standard carb without a hot air pipe ??? Pre-heated air will help to air/fuel mixture to atomize better..... it's all in the shape of the intake manifold that causes the problem without the hot air pipe.

Tim, Do you have installed one of the "pre-heaters" that pulls hot air off the exhaust manifold and runs the hot air through the carburetor?....Michael Pawelek

The car has a NH carb and a hot air pipe.

Try a Champion X plug in # 1 & go for a ride. New replacement plugs run cooler

#1 is running too cold. Logic says a thermostat and maybe a waterpump are better fix than X plugs, as then the cyl will run at efficient temperature.

rdr

Tim,
Do you have a water pump? Your engine might be running too cold. The number 1 cylinder would be the coldest because it is on a direct path between the water intake and outlet.

I have been running a NH with the hot air pipe and no water pump with autolite plugs Never had a plug foul. My other car has a Kingston L4 with a hot air pipe and motorcraft plugs, and no water pump. Never had a plug foul either. The 3rd car has no water pump NH carb with hot air intake and motorcraft plugs. I've only had this car running for a year, but so far no fouling either. The first two cars have high heads, and the 3rd car has a low head. All engines use magneto, coils and timers.
Norm

If you think you have a bad valve, try a compression test. A little Marvel Mystery Oil (or your favorite kind of top oil) would help with sticky valves and rings. I had a problem with plug fouling one time. It turned out to be a weak (old) battery (I don't have a mag). Following this reasoning, it could be bad (weak) coils. One other thought, there was a time when the new plug wires sold had a problem with the solder not being stuck to the terminal. It looks like it is, but when you touch it, it's not! I've also heard of timer wire terminals having a similar problem but have not experience that for myself.
Verne Shirk
Wichita, KS

The car does not have a water pump, it has the original radiator, high head, coils, new day timer. It had new motorcraft plugs less than 25 miles of driving on them. I was driving at a low speed when it fouled.

Tim: Motorcraft plugs run cool. The Champion X plug is a hot plug. There's a lot of NOS Champ's around... better than the re-pro Champion X's with malformed threads.

You can try to put a reducer insert in the spark plug hole and purchase a modern hot plug to see if it fixes the fouling. I use the Champion RN 16 YC plugs. They are the hottest in that series which runs from the cold 10 all the way to the hot 16. If they do not work, it is time for a rebuild. Do not buy the RN16YC4 plugs as they are for smogged out California crap cars. Watch out for the last four. The Auto parts store will get arrested if they sell you a non (4) plug if you have a California car and they are tough about it so tell them your car is a Model T.

The plug has a resistor and is not available without one. They have a standard projected nose. They are 14mm with a 3/4" reach and have a 13/16th " hex. They cost about 99 cent each so it is a cheap fix. Remember, do not get them if they insist on selling you ones with a four (4) on the end because they do not want to go to jail.

The Motorcraft plugs don't work worth poo with stock ignition system. I tried a set several years ago and they would foul in a short drive. Put Champion X plugs in all my cars, gapped at .025" haven't fouled a plug since in thousands of miles driving.

Ford should not let their name be used on the motorcrap plugs being sold today. The quality is bad and some of the plugs will not work straight out of the box. I am running used X plugs in all of my T's. No problems.

Paul

X is the only mark for this spot. I only run vintage ones not new X copys.

Makes no sense to blame sparkplugs when the engine is running too cold on #1 and the others are often run too lean.

I ran these same Motorcraft plugs in a high head in the '98 Greatrace, and here with a low head in the '99 race, and many miles in between. Never had one foul. Outside temps varied from 30 to 120 degrees. 180 thermostat and waterpump are the key to efficient motoring.

rdr

Those brass discs keep most of the trash out of the plugwells.

I run Bosch 3203 five years and haven't looked at them,start every time no misses,two national tours this year to 12183 ft elevation with no problems,but several people had Motorcraft with no problems.
Rick

I put a used Motorcraft plug in and changed the New Day timer to an orginal cummutator. I drove the car 50 or 60 miles to day in high 80s to 90 degree the car ran fine and the motor ran smooth. I have not pulled the plugs but it ran much better.

Ralph,

I gotta call BS on that. I run all year round except the Christmas parade (subzero some times) without a heat pipe and never foul a plug. Never.

Must have been a bad New Day timer......

OOPS.

I should not have spouted off about the Motorcraft plugs. I went out to the shop to check and the last Motorcraft plugs I bought are fine. It was a set of Champion A-25 plugs that I bought a couple of years ago. They were shoddy with malformed threads and crooked electrodes. They say that the memory is the second thing to go and I can't remember what the first is.

Paul

If you like running the hottest plugs in order to run an unevenly cold engine, Royce, it's your choice.

Paul, I had been warned about the shoddy A-25 when I bought my Motorcrafts from the local T&A store.

rdr