2005 Yamaha F90TR 90HP Outboards Factory Service Manual, Page 51Get this manual
Fuel filter and fuel pump 3Slowly let up on the plunger and diaphragm, and then remove them Checking the diaphragm and valves
1Check the diaphragm for tears and the valves for cracksReplace if necessary
Assembling the fuel pump
NOTE: Clean the parts and soak the valves and the diaphragm in gasoline before assembly to obtain prompt operation of the fuel pump when starting the engine1Align the plunger and diaphragm installation holes a, and then install the plunger into the diaphragm2Push down on the plunger and the diaphragm, and then install the pin 1