Honda BF50 (5HP) BF5A Outboard Motors Shop Manual., Page 80Get this manual
HONDA 6THROTTLE OPENER SYSTEM
aDESCRIPTION
The throttle opener system allows the carburetor throttle valve to open to the most suitable position for starting (approxgo),even if the throttle grip is in the "SLOW" positionStarting ability is greatly improved by this system
bCONSTRUCTION
The carburetor throttle lever connected to the throttle link by the throttle rodThe diaphragm rod contacts the throttle linkThe diaphragm chamber is connected to the intake manifold with the rubber tube which has check valve
Before starting engine After starting engine
THROTTLE VALVE