Testing Mechanical Fuel Pump; Mechanical Fuel Pump; Replacement - Mercury 305 CID Service Manual

Testing Mechanical Fuel
Pump
NOTICE
Refer to "Precautions," in this section,
BEFORE proceeding.
1. Disconnect battery cables from battery.
2. Remove fuel line from carburetor or outlet side of
fuel pump.
3. Install Fuel Pressure Connector (91-18078) to
carburetor and reinstall fuel line. Tighten connec-
tor and fuel line securely.
4. Connect fuel pressure test gauge to connector.
5. Reconnect battery cables, start engine, and run
at 1800 RPM.
6. Fuel pressure should be within specifications. If
not, replace fuel pump.

Mechanical Fuel Pump

NOTICE
Refer to "Precautions," in this section,
BEFORE proceeding.

Replacement

IMPORTANT: The fuel pump cannot be repaired.
If pump fails, it must be replaced.
Index
90-823225--1 1096
1. Disconnect battery cables from battery.
Plug fuel supply hose after removal to prevent
fuel from leaking into boat.
2. Use a wrench to stabilize brass coupling at fuel
filter inlet fitting, loosen fuel line fitting, disconnect
and suitably plug fuel line to prevent fuel in tank
from leaking into bilge.
3. Remove fuel filter.
4. Using wrench to stabilize brass couplings on fuel
pump, loosen fuel line fittings and disconnect
from fuel pump.
5. Clean gasket from seawater pump.
6. Apply Quicksilver Perfect Seal to both sides of
fuel pump gasket and install on fuel pump.
7. Install fuel pump. Torque bolts to 25 lb. ft.
(34 N·m).
8. Install fuel inlet and outlet fittings to fuel pump
as outlined next:
Avoid gasoline fire or explosion. Improper instal-
lation of brass fittings or plugs into fuel pump or
fuel filter base can crack casting and/or cause a
fuel leak.
Apply #592 Loctite Pipe Sealant with Teflon to
threads of brass fitting or plug. DO NOT USE
TEFLON TAPE.
Thread brass fitting or plug into fuel pump or
fuel filter base until finger tight.
Tighten fitting or plug an additional 1-3/4 to
2-1/4 turns using a wrench. DO NOT
OVER-TIGHTEN.
Install fuel line. To prevent over-tightening,
hold brass fitting with suitable wrench and
tighten fuel line connectors securely.
Check for fuel leaks.
9. Install sight tube.
10. Install fuel line and fuel filter.
11. Reconnect battery cables.
12. Make sure water is supplied to cooling system
72677
and start engine. Check for fuel leaks.
FUEL DELIVERY SYSTEMS AND FUEL PUMPS - 5A-9
! CAUTION
! WARNING