10-11-17, 07:27 PM
the gauges measure vacuum so the only way to calibrate them is with vacuum that is why you plug them into one carb if it reads at say 12 oclock then you set the rest to read the same on the same carb then when you plug them in to the carbs for balancing then you will get the exact same vacuum when you adjust them to read the same it is the only way to get accurate carb balancing with them cheep gauges far better of with mercury gauges they never go out of calibration