Table of Contents
Advertisement
Service Procedures
5.
Install the fuel hose to the high pressure fuel filter. Secure the fuel hose to the high pressure fuel filter with a spring clamp.
b
a
Description
Bolt securing high pressure fuel filter bracket
Vapor Separator Tank (VST)
VST Removal
Performing service or maintenance without first disconnecting the battery can cause product damage, personal injury, or
death due to fire, explosion, electrical shock, or unexpected engine starting. Always disconnect the battery cables from the
battery before maintaining, servicing, installing, or removing engine or drive components.
Fuel is flammable and explosive. Ensure that the key switch is off and the lanyard is positioned so that the engine cannot
start. Do not smoke or allow sources of spark or open flame in the area while servicing. Keep the work area well ventilated
and avoid prolonged exposure to vapors. Always check for leaks before attempting to start the engine, and wipe up any
spilled fuel immediately.
Failure to release pressure from the fuel system will result in fuel spraying out, which can cause a fire or explosion. Allow the
engine to cool completely and release all fuel pressure before servicing any part of the fuel system. Always protect eyes and
skin from pressurized fuel and vapors.
1.
Disconnect the battery cable from the battery.
2.
Install a fuel pressure gauge onto the fuel rail Schrader valve and release any pressurized fuel into an appropriate
container.
a
Fuel Pressure Gauge Kit
Dual Fuel/Air Pressure Gauge Kit
Page 3C-20
c
a -
b -
c -
d
d -
e -
e
16852
WARNING
!
WARNING
!
CAUTION
!
a -
10216
© 2016 Mercury Marine
Spring clamp securing fuel hose
Oil filter
Bolt securing high pressure fuel filter bracket
High pressure fuel filter
Water separating fuel filter
Nm
6
Schrader valve
91‑881833A03
91‑881834A 1
90-8M0105568 eng MARCH 2016
lb. in.
lb. ft.
53
Advertisement
Chapters
Table of Contents
Troubleshooting
Need help?
Do you have a question about the 25 EFI and is the answer not in the manual?
Questions and answers
Where to find the serial numer
The serial number on a Mercury 25 EFI is located on the outboard motor.
This answer is automatically generated
Have no spark and have new stator and new trigger, rectifier, new coils and new spark plugs. I have checked remote kill switch and ohmed out good, and even disconnected and still no spark. The wire from remote to engine plugs is black/yellow, but not sure what color it changes to on the engine side. I **** at a lost
Possible causes of no spark in a Mercury 25 EFI after replacing the stator, trigger, rectifier, coils, and spark plugs include:
1. Incorrect or Loose Ignition Coil Installation – Ensure ignition coils are securely installed onto the spark plugs.
2. Wrong Spark Plugs – The engine may not run or spark correctly if incorrect spark plugs are used.
3. Faulty Connectors or Wiring – Inspect connectors for corrosion, loose wires, or pushed-back pins. Ensure all connectors are properly seated.
4. Damaged Wiring Harness – Look for pinched, cut, or chafed wires in the harness.
5. PCM or Sensor Issues – If all cylinders exhibit similar symptoms, a sensor or harness input to the PCM may be faulty.
6. Faulty Grounds or Loose Ring Terminals – Secure all ground connections and ring terminals.
If the issue persists, reviewing the PCM fault history using the CDS may help diagnose the problem.
This answer is automatically generated