Yamaha GX1800A, Service Manual

Page: 14 / 32

11
ETV failure
control ETV failed, or open or
short circuit is
detected in ETV
circuit. • Opening angle of the ETV
is fixed to the default
opening angle.
• Maximum engine speed is
limited to approximately
2500 r/min.
• Ignition timing is con-
trolled.
Battery dis-
connection
warning Battery lead is discon-
nected during normal
operation Control is performed using
the same actions as the
ETV failure control.
Idle speed
control Throttle lever is in the
fully closed (idle)
position. Engine speed is limited to
1150–1350 r/min.
Over revolu-
tion control Engine speed exceeds
7800 r/min. Ignition is controlled.
Condi-
tion Action
Normal None
Level 1 Ignition is cut off
to 1 cylinder.
Level 2 Ignition is cut off
to 2 cylinders.
Level 3 Ignition is cut off
to 3 cylinders.
Level 4 Ignition is cut off
to all cylinders.
High intake
air pressure
control In a state where
engine speed has
exceeded 7550 r/min
and intake pressure is
higher than 177 kPa
(25.7 psi) has lasted
longer than 1.5 sec-
onds. The throttle valve is limited
from opening more than the
point where the control was
engaged. Completely shutting off the
throttle valve will disengage
the control.
Knock control When engine speed
exceeds 2000 r/min
after warming up
Ignition timing is delayed
according to the volume of
knocking
Item Condition Action Remarks