Evinrude E-tec 75 HP, Service Manual

Page: 110 / 344

110
SYSTEM ANALYSIS
SPECIALIZED TEST PROCEDURES
SPECIALIZED TEST
PROCEDURES
The following tests are performed with the out-
board running. Observe the operation of each
electrical circuit. Look for inconsistencies between
similar circuits and variations in cylinder perfor-
mance.
Dynamic Tests
Use the diagnostic program to perform Dynamic
Fuel and Ignition tests. These tests can be used to
momentarily stop injector or ignition function for a
selected cylinder while the outboard is running.
This is an effective tool for checking the perfor-
mance of each cylinder. Comparing one cylinder’s
performance to others can frequently isolate a cyl-
inder that is not operating properly.
IMPORTANT:
DO NOT misinterpret tests run at
IDLE. The idle speed controller in the
EMM
com-
pensates to maintain a constant engine speed at
IDLE. The
Dynamic Tests
screen of the diagnostic
software includes a function to temporarily disable
the idle controller.
Dynamic Tests
can be used in conjunction with:
•
A timing light to determine how other cylinders
are affected by one cylinder being “dropped”; or
•
A voltmeter to check voltage changes on electri-
cal circuits.
IMPORTANT:
Test the outboard while the run-
ability issue is present. Use the test procedures to
identify inconsistencies in voltages and cylinder
performance. Once a circuit has been identified as
malfunctioning, a thorough inspection of all
related wiring and connections must be per-
formed. Check all voltage inputs and grounds; and
perform resistance tests for all circuits prior to
replacing any suspect components.
Testing with Timing Light
An inductive timing light can be used to monitor
ignition system output and the activation of fuel
injectors and the oil injection pump. DO NOT
clamp timing light pick-up on more than one wire
at a time. Avoid erratic timing light reading by iso-
lating pick-up from other wires. Self powered tim-
ing lights offer the convenience of no power
cables and can help eliminate false signals.
DANGER
Contact with a rotating propeller is likely
to result in serious injury or death. Assure
the engine and prop area is clear of people
and objects before starting engine or
operating boat. Do not allow anyone near
a propeller, even when the engine is off.
Blades can be sharp and the propeller can
continue to turn even after the engine is
off. Remove propeller before servicing
and when running the outboard on a flush-
ing device.
DO NOT run the engine indoors or without
adequate ventilation or permit exhaust
fumes to accumulate in confined areas.
Engine exhaust contains carbon monox-
ide which, if inhaled, can cause serious
brain damage or death.
Dynamic Tests Screen 005167
WARNING
The electrical system presents a serious
shock hazard. DO NOT handle primary or
secondary ignition components while out-
board is running or flywheel is turning.