OK, I have installed 6 new AC45 plugs, gapped at .035. The old plugs that I removed were Champion RJ12YC. The old plugs were extremely black and sooty. This was the case with every plug, not just a few. So the engine has been running very rich. This might be since I've owned it, or before. I'm guessing that it's since I've owned it because I definately removed the old plugs and re-gapped them months ago when I first started the truck. My carburetor is a Carter YF966S, which I cleaned and put a carb king kit in it, back before initial starting. The carb seems to work OK, but I have to confess, I don't really know the proper way to adjust it. I'm pretty good at many phases of this hobby, but diagnosing a poor running engine is not one of them. I've never been good at that. Here's a clue that seems odd to me: The engine starts right up when cold and full choke on. But when it's warmed up, I still have to choke it most times. That seems pretty odd to me. I have not adjusted the valves yet, and I know that's important. But, it doesn't seem to me that that would be part of this problem.
Last edited by Mike Burns; 08/21/2025 3:37 PM.
