Chrysler 75 and 85 HP Outboards Service Manual OB 3646, Page 34Get this manual
Subsection
FUELPUMP
GENERAL
The information in this subsection is concerned with the removal, repair, and installation of the fuel pumpDescriptionA 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 fuel fine mesh screen filters the fuel as it enters the pumpAs the diaphragm flexes out, it transfers fuel internally to the second stageThe 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