165
FUEL SYSTEM
FUEL COMPONENT TESTS
7
Fuel Supply
Fuel System Pressure Test
Relieve fuel system pressure. See
Relieving Fuel
System Pressure
on p. 168.
After relieving fuel system pressure, install a 0 to
100 psi (0 to 690 kPa) Fuel Pressure Gauge,
P/N 5000902 or equivalent, to the upper fuel pres-
sure test fitting.
START outboard and check pressure. System
pressure should be 20 to 30 psi (138 to 207 kPa).
Shut OFF outboard. Monitor pressure gauge.
Pressure should not drop below 15 psi (103 kPa).
IMPORTANT:
If outboard does not run, prime
fuel system and crank outboard; check circulation
pump operation; check fuel system pressure.
Relieve fuel system pressure before removing fuel
pressure gauge. See
Relieving Fuel System
Pressure
on p. 168.
Results:
Normal pressure
•
Observe pressure reading after outboard is shut
OFF.
•
Proceed to
Lift Pump Pressure Test
on
p. 166.
Pressure drops after outboard shut OFF
•
Leaking fuel injector
•
Leaking pressure regulator
•
External fuel system leak
High pressure
•
Suspect damaged pressure regulator in vapor
separator, restricted fuel return manifold, or
vapor separator fitting.
Low pressure
•
Check fuel supply to fuel lift pump. Refer to
Lift
Pump Vacuum Test
on p. 167. Higher vacuum
readings indicate restrictions in the fuel supply.
Repair or replace as needed.
•
Lift pump not supplying adequate fuel to vapor
separator. Refer to
Lift Pump Pressure Test
on p. 166.
•
If the above requirements are met and vapor
separator remains full of fuel, suspect damaged
circulation pump. Replace vapor separator
assembly.
No pressure
•
Check electrical circuit and ground connections
for circulation pump.
•
Voltage present and pump does not run. Repair
connection or replace vapor separator assem-
bly.
Pressure Regulator Test
Refer to “Vapor Separator” on page 170 to
remove vapor separator. Apply oil to valve and
connect pressure pump and hose to the fuel
return fitting of vapor separator. Apply pressure to
check regulator operation. The pressure should
WARNING
Use caution when working on any pres-
surized fuel system. Wear safety glasses
and work in a well ventilated area. Extin-
guish all smoking materials and make
certain no open flames or ignition
sources exist. Failure to properly relieve
fuel system pressure can result in spray-
ing fuel and/or excessive fuel spillage
during servicing. Fuel is flammable and
can be explosive under certain condi-
tions.
1.
Test fitting
2.
Fuel pressure gauge
005009
2
1
Summary of Contents for E-tec 75 HP
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Page 233: ...233 POWERHEAD POWERHEAD VIEWS 10 POWERHEAD VIEWS Port Short Block Starboard Short Block ...
Page 234: ...234 POWERHEAD POWERHEAD VIEWS Port Dressed Powerhead Starboard Dressed Powerhead ...
Page 235: ...235 POWERHEAD POWERHEAD VIEWS 10 Front ...
Page 236: ...236 POWERHEAD POWERHEAD VIEWS Rear ...
Page 237: ...237 POWERHEAD POWERHEAD VIEWS 10 Top ...
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