I would like to buy a new set of 8 sparks.
I didnt find the MOTOCRAFT AL7C SPARK PLUGS 49 50 so I'am looking for alternative.
My questions :
Is the Set of 8 Autolite 216 Spark Plugs Ford Mercury Flathead V8 239 255 compatible with my Mercury Coupe engine v8 4.2 1949 9M 255.4 ?
I had bought new set in ITALY but I had to clean, check and fit the old MOTORCRAFT AL7C ones.
The attached photo is of the new one (all 8 were like this) which gave me obvious combustion problems (it looks like oil from the filter!?) but I did maintenance on the carburetor and struggled to start it several times because the automatic air synthesiser does not work well ... however I think I put too much gasoline .. in fact the engine was sputtering at high revs.
At the moment with the old ones installed the engine runs well and I have no explosions.
very best
Autolite 216 is correct heat range and reach for your Mercury. I use them in my Mercury.
You spark plug looks carbon fouled. This can happen if the carburetor needs to be rebuilt or you do not drive it long enough to get the engine fully warmed up ( about 30 minutes ). Check your tail pipe for carbon build up. If there is build up there, your engine is not burning all of the fuel delivered.
Your choke (air synthesizer) should be closed when the engine is cold and open fully when the engine temperature is in the middle of the gauge (about 82 C), If it does not do this, clean the choke linkage and make sure that it does not bind.
Tom
Yes, i know the air synthesizer should be closed when the engine is cold ....
infact it doesn't work correctly so i have to close manualy. I'll will drive for more then 30 mn and check if sparks are clean or carbon fuel again
best
Francesco