1979 Johnson 150 V6 has three carbs stacked.<br />The 2 on the bottom have the choke flaps that can be engaged(closed)at the key switch via solenoid or manually. The top one doesn't have one?? There is a roller pin across the front of the intakes where the two flaps are attached with tiny screws, that rotates to open and close them. There is a roller pin in the top carb, but no flap, or holes for evidence there ever was one. I bought the Clymer book yesterday, but can't find any verification if this is a design function. Anyone know??