Outboard motor troubleshooting
4-11
Symptom 1: High engine idle speed.
Symptom 1: Limited engine speed (below 2000–3000 r/min).
Compression pres-
sure is low
Improper valve timing
Check the valve timing. 7-13
Check the timing belt. 7-13
Compression leakage
Measure the valve clearance. 7-2
Check the rocker arm for damage. 7-37
Check the camshaft for damage. 7-38
Check the valve and valve seat for
we
ar.
7-32
7-34
Check the piston and piston ring for
dama
ge.
7-46
Check the cylinder for scratches. 7-48
Symptom 2 Cause Checking steps
See
p
age
—
Air leakage (throttle valve–
cylin
der head)
Check the gaskets of the intake
manif
olds and throttle body.
6-19
Check the intake manifold for
cr
acks.
6-21
Throttle link rod and the
thrott
le cable are not
installed properly
Adjust the throttle link rod and the
throttle cab
le.
6-22
3-6
ISC valve malfunction
Check the ISC valve operation using
the YDIS
.
5-20
Measure the ISC valve resistance. 5-20
Symptom 2 Cause Checking steps
See
p
age
Buzzer comes on,
o
verheat alert indica-
tor comes on
Clogged cooling water inlet
Check the pilot hole for cooling
w
ater discharge.
10-9
Check the cooling water inlet. 10-15
Water pump malfunction
Check the impeller. 8-4
Check the impeller key. 8-4
Check the insert cartridge. 8-4
Water leakage from water
pump hou
sing
Check the water pump housing. 8-4
Check the outer plate cartridge. 8-4
Clogged cooling water pas-
sages
Check the cooling water passages. 2-23
Open PCV Check the PCV. 9-19
Thermostat malfunction Check the thermostat. 7-26
Symptom 2 Cause Checking steps
See
p
age
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