My 1954 3100 235 has not been tuned up in a while. It has always ran great. It is now cold and I started it up to warm up before I left the house. As usual, I had to have full choke until the engine slightly warmed up and then I only back off the choke a little bit. Recently I noticed it seemed to be running just a little bit rough. It was hard to hear a distinct miss fire. I later noticed the exhaust left a residue on the driveway. Very heavy carbon build up. It was much darker than the pictures really shows. Two different days. It looks lighter in the picture for some reason.
For the engine experts, does the heavy carbon exhaust tell you anything about the engine performance and what I might need to change/fix? Simple tune-up? Timing? ?????
