Chrysler 70, 75 and 85 HP Outboard Motors Service Manual OB 3438, Page 34Get this manual
Subsection
_ FUELPUMP
GENERAL
The information in this subsection is concerned with the removal, repairand installation of the fuel pump DescriptionA two stage diaphragm displacement fuel pump is used to lift fuel from the fuel tank and direct it to the carburetors
(center) make the diaphragm flex in and draw in fuelA fine mesh screen filters the fuel as it enters the pump As the diaphragm flexes out, it transfers fuel internally to the second stage The second stage delivers fuel to the carburetors when changes in crankcase pressure of the NO cylinder (bottom) make the diaphragm flex out and send fuel to the carburetors