Cab.
Plugs are a light brown. I forgot to mention I have played with the carb. I've adjusted the air door both ways, bought a carb tuning kit and have tried numerous combinations of metering rods, jets, adjusting the setting on the accelerator pump. none of the changes have made a bit of difference. If it had made even a slight difference, good or bad at least I would know I'm on the correct path.
That carb has been off and on more than a prom dress.