Anyone know of a source for an overview of Keihin stock carb function? i.e. what the various adjustments do, and where fuel mix changes occur? I've worked on Dellorto, Bing, and Amal motorcycle carbs, but these are new to me. Is the pilot screw an air screw or a fuel screw (does adjusting that screw add and remove air or fuel (various carbs do it one way of the other)
Also, what is the 1/2 inch long brass nipple coming out of the bottom of the carb near the float bowl gasket, with a hose to the intake manifold. Is it a float bowl breather or vent? Can I plug it, or does it need to breathe?