Honda BF35A-BF45A Outboard Motors Shop Manual., Page 55Get this manual
HONDA BF35A-45A
7)With the vacuum of the No3 carburetor being the standard, turn the No1 and No2 carburetor adjusting screws so that the vacuum gap between the No1 and No2 carburetors is 20 mrnHg or belowSnap the engine several times and be sure that the vacuum of the No1 and No2 carburetors is the same as that of the No3 carburetor
The less the vacuum gap is, the more the idle speed stabilizes
11I THROTTLE STOP SCREW
8) Remove the special tool from the intake manifold and install the 10 mm plugs9) After adjustment, readjust the idling speed by turning the No3 carburetor throttle stop screw (page 3-8)