Spark Plugs have black soot

[William B.]

Cannot eliminate my R45S plugs getting black soot on them on my 2 x 4's on my 61. They are not wet with oil, just dry soot. Have adjusted air/fuel mixture screws to get best idle and vacuum. Car runs really great on the road and in town, but everytime I start up the car when it is cold, black soot mixed with water (doesn not have gas smell) comes out first the driver pipe then the passenger side pipe. After about 3 minutes, the water and soot mixture stop and it runs clean. I am convinced the liquid is not gas, but regardless, I cannot get the black soot to stop coming out the pipes on startup. The carbs are not original, but are WCFB's. Timing is good, dwell is good on the dual point ignition. According to my carter carb book, the primary jets are oversize by about .024". Could this be the problem?

Thanks for any help,

Bill