MerCruiser 13, Service Manual

Page: 267 / 348

5A - 2 - FUEL PUMP 90-816462 2-695
Precautions
! WARNING
Always disconnect battery cables from battery
BEFORE working on fuel system to prevent fire
or explosion.
! WARNING
Be careful when changing fuel system compo-
nents; gasoline is extremely flammable and high-
ly explosive under certain conditions. Be sure
that ignition key is OFF. DO NOT smoke or allow
sources of spark or flame in the area while chang-
ing fuel filters. Wipe up any spilled fuel immedi-
ately.
! WARNING
Make sure that no fuel leaks exist before closing
engine hatch.
! CAUTION
DO NOT operate engine without cooling water be-
ing supplied to seawater pickup pump, or pump
impeller will be damaged and subsequent over-
heating damage may result.
! WARNING
Avoid gasoline fire or explosion. Improper instal-
lation of brass fittings or plugs into 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 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.
Fuel Delivery System
Recommendations
! WARNING
Boating industry standards (BIA, ABYC, etc.) fed-
eral
standards and Coast Guard regulations
MUST BE adhered to when installing fuel delivery
system.
When designing and installing fuel delivery system,
the following information MUST BE observed:
1. Fuel tank should be mounted below carburetor
level, if possible. If tank is mounted above carbu-
retor level, gravity feed may cause carburetor fuel
inlet needle to unseat, and flooding may result.
2. Fuel pickup should be at least 1 in. (25 mm) from
the bottom of the fuel tank to prevent picking up
water or other impurities.
3. Fuel lines used MUST BE Coast Guard approved
(USCG type A) and MUST NOT BE SMALLER
THAN 3/8 in. (9.5 mm) I.D. On installations where
long lines or numerous fittings are required, larg-
er size lines should be used.
4. Fuel line should be installed free of stress and
firmly secured to prevent vibration and/or chaf-
ing.
5. Sharp bends in fuel line should be avoided.
6. A flexible fuel line must be used to connect fuel
line to engine to absorb deflection when engine is
running.
Description
The fuel system consists of fuel tank(s), a water sepa-
rating fuel filter, an electric fuel pump and a carbure-
tor.
The fuel is stored in the fuel tank. When the fuel pump
is energized by turning on ignition switch, fuel is
drawn from the fuel tank, through the water separat-
ing filter, by the electric fuel pump.
The fuel is pushed through the fuel line to the carbure-
tor where it is metered and supplied to the engine.