Honda Outboards BF40A/BF50A Service Manual, Page 55Get this manual
HONDABF3r5A45A 71 With the vacuum of the No3 carburetor being the stan dard, turn the No.1 and No.2 carburetor adjusting screws so that the vacuum gap between the No.1 and No2 car
buretors is 20 mmHg or below Snap the engine times and be sure that the vacuum
of the No.1 and No carburetors is the same as that of the No.3 carburetor
NOTE The less the vacuum gap isthe more the idle speed stabilizes8) Remove the special tool from the intake manifold and install the 10 mm plugs9) After adjustmentreadjust the idling speed by turning the No.3 carburetor throttle stop screw (page 3-BI