Yamaha F150A, Service Manual

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2-5
Electronic control system
Engine speed control
The engine ECM decreases the engine speed to protect the engine from damage and to improve
the smoothness of gear shifting.
Control
name
Criteria Description
Over-
revving
control
When engine speed
is more than a
predetermined level
(F150A, FL150A)
6200–6301 r/min
Fuel injection will be skipped
for cylinders #1 and #4.
6302–6551 r/min
Fuel injection will be skipped
for cylinders #1, #4 and #3.
Over 6551 r/min
Fuel injection for all cylinders
will be skipped.
When engine speed
is more than a
predetermined level
(F150B, FL150B)
5751–5852 r/min
Fuel injection will be skipped
for cylinders #1 and #4.
5853–6102 r/min
Fuel injection will be skipped
for cylinders #1, #4 and #3.
Over 6102 r/min
Fuel injection for all cylinders
will be skipped.
Multi-
engine
system
control
Multi-engine system
switch is ON
When using dual outboard
motors with a dual switch
panel, if the overheat control
or low oil pressure control is
activated, then these are to
be activated in the same way
for the other outboard motor
that is operating normally.
Fuel injection will be skipped
in stages to limit engine
speed to approximately
2000–3500 r/min.
Shift cut-
off
control Shift cut-off switch is
ON, engine speed is
400–2000 r/min
This allows smooth engagement and disengagement of the
dog clutch.
400–729 r/min Retards ignition timing.
730–1999 r/min
After firing will be skipped for
cylinders #1 and #4, retards
ignition timing.
Over-
heat
control
The thermoswitch is
ON
No determination on overheat
will be made until the engine
speed is more than 2000
r/min for 29 seconds or more
after the engine has started,
or until 74 seconds after the
engine has started. Fuel injection will be skipped
in stages to limit engine
speed to approximately
2000–3500 r/min.
The overheat alert indicator
comes on, and the alert
buzzer sounds.
Low oil
pressure
control
The pressure
decreases to less
than 272 kPa
(2.72 kgf/cm
2 ,
39.4 psi).
Fuel injection will be skipped in stages to limit engine speed to
approximately 2000–3500 r/min.
The low oil pressure alert comes on, and the alert buzzer
sounds.