Mercury 25 EFI Service Manual page 199

7. Align the diaphragm tab with the fuel pump diaphragm housing key.
8. With the diaphragm tab located in the fuel pump diaphragm housing key, check to ensure the drain hole in the end of the
plunger is opposite the fuel pump diaphragm housing plunger guide opening. If the orientation of the plunger is not correct,
the diaphragm pin must be removed, and the plunger rotated 180° to correct the alignment.
a
9. Align the check valve assembly and the fuel pump diaphragm housing. The check valve assembly fuel inlet must be
orientated in the same direction as the plunger drain hole on the fuel pump diaphragm housing.
10. Install the fuel pump screws. Tighten the fuel pump screws to the specified torque.
11. Install the O‑ring.
b
a
Description
Fuel pump screws (T20H Torx)
90-8M0105568 eng MARCH 2016
a - Diaphragm tab
a
b - Fuel pump diaphragm housing key
b
10040
a - Fuel pump diaphragm housing plunger guide opening
b - Plunger drain hole
b
10041
a
a - O‑ring
b - T20H Torx screw
10032
a - Check valve assembly fuel inlet
b - Plunger drain hole on the fuel pump diaphragm
housing
b
10044
© 2016 Mercury Marine
Service Procedures
Nm lb. in. lb. ft.
5.5 50
Page 3C-15