check engine YAMAHA VX110 2005 User Guide

5-5
EPOWRENGINE UNIT
5. Measure:
Compression pressure
Out of specification →
Refer to steps (b)
and (c).
6. Install:
Spark plug
Minimum compression pressure
(reference data):
1,150 kPa
(11.5 kgf/cm
2, 164 psi)
Measurement steps:
a. With the throttle wide open, crank the
engine until the reading on the compres-
sion gauge stabilizes.
NOTE:
The difference in compression pressure
between cylinders should not exceed 100
kPa (1 kgf/cm2, 14 psi).
b. If the compression pressure is extremely
high, check the cylinder head, valve sur-
faces and piston crown for carbon depos-
its.
Carbon deposits →
Eliminate.
c. If the compression pressure is below the
minimum specification, squirt a few drops
of oil into the cylinder and measure
again.
Refer to the following table.
Compression pressure
(with oil applied into the cylinder)
Reading Diagnosis
Higher than
without oilPiston ring wear,
piston wear or
damage
→ Repair.
Same as without
oilValves, cylinder
head gasket or pis-
ton possibly defec-
tive
→ Repair.
T R..
Spark plug:
13 N  m (1.3 kgf  m, 9.4 ft  lb)
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E
–+ELEC
INDICATION SYSTEM .................................................................................. 7-48
WIRING DIAGRAM ................................................................................. 7-48
FUSE ....................................................................................................... 7-50
BATTERY ................................................................................................ 7-50
MAIN AND FUEL PUMP RELAY............................................................. 7-50
ECM......................................................................................................... 7-50
ENGINE TEMPERATURE SENSOR ...................................................... 7-50
THERMOSWITCH (ENGINE).................................................................. 7-50
THERMOSWITCH (EXHAUST) .............................................................. 7-50
REMOTE CONTROL UNIT (DELUXE MODEL ONLY) ........................... 7-50
BUZZER .................................................................................................. 7-50
OIL PRESSURE SWITCH ....................................................................... 7-51
MULTIFUNCTION METER...................................................................... 7-51
Multifunction meter ............................................................................ 7-51
MULTIFUNCTION METER REMOVAL ................................................... 7-51
Display function (Sport model only) .................................................. 7-52
Display function (Deluxe model only) ................................................ 7-53
Speedometer display ........................................................................ 7-54
Tachometer display ........................................................................... 7-55
Hour meter display ............................................................................ 7-55
Voltage meter display........................................................................ 7-55
Low oil pressure warning indicator .................................................... 7-55
Fuel level meter display and fuel warning indicator .......................... 7-55
Overheat warning indicator ............................................................... 7-56
Check engine warning indicator ........................................................ 7-56
Diagnostic display ............................................................................. 7-57
REMOTE CONTROL SYSTEM (DELUXE MODEL ONLY) .......................... 7-58
WIRING DIAGRAM ................................................................................. 7-58
REMOTE CONTROL SYSTEM ............................................................... 7-59
Yamaha Security System indicator ................................................... 7-59
Low-rpm mode indicator.................................................................... 7-59
Checking the remote control transmitter ........................................... 7-60
Transmitter registration ..................................................................... 7-62
Replacing of the transmitter battery .................................................. 7-63
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7-10
E
–+ELECELECTRICAL ANALYSIS
Low resistance measurement
NOTE:
When measuring a resistance of 10 Ω
or less
using a digital tester, the correct measure-
ment cannot be obtained because of the
tester’s internal resistance.
To obtain the correct value, subtract the
internal resistance from the displayed mea-
surement.
The internal resistance of the tester can be
obtained by connecting both of its terminals.
Correct value =
Displayed measurement –
Internal resistance
Peak voltage measurement
NOTE:
When checking the condition of the ignition
system it is vital to know the peak voltage.
Cranking speed is dependant on many fac-
tors (e.g., fouled or weak spark plugs, a
weak battery). If one of these is defective,
the peak voltage will be lower than specifica-
tion.
If the peak voltage measurement is not
within specification the engine will not oper-
ate properly.
A low peak voltage will also cause compo-
nents to prematurely wear.
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7-11
E
–+ELECELECTRICAL ANALYSIS
Peak voltage adapter
NOTE:
Throughout this chapter the part numbers of
the specified peak voltage adapters have
been omitted. Refer to the following part
numbers.
The peak voltage adapter should be used
with a digital tester.
When measuring the peak voltage, connect
the peak voltage adapter to the digital circuit
tester and switch the selector to the DC volt-
age mode.
NOTE:
Make sure that the adapter leads are prop-
erly installed in the digital circuit tester.
Make sure that the positive pin (the “+” mark
facing up as shown) on the adapter is
installed into the positive terminal of the
tester.
The test harness is needed for the following
tests.
È Voltage measurement
É Peak voltage measurement
Test harness
NOTE:
If the lighting coil and pickup coil(s) are mea-
sured unloaded, disconnect the test harness
on the output side coupler.
Peak voltage adapter:
YU-39991
Peak voltage adapter B:
90890-03172
Checking steps:
Disconnect the coupler connections.
Connect the test harness between the
couplers.
Connect the tester terminals to the termi-
nals which are being checked.
Run the engine and observe the mea-
surement.È
É
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7-14
E
–+ELECIGNITION SYSTEM
IGNITION SPARK
WARNING
When checking the spark gap, do not
touch any of the connections of the spark
checker/ignition tester lead wires.
When performing the spark gap test, take
special care not to let sparks leak out of
the removed spark plug cap.
When performing the spark gap check,
keep flammable gas or liquids away,
since this test can produce sparks.
1. Check:
Ignition spark
Weak →
Check the ECM output peak
voltage.
Check the ignition coil for resistance.
Checking steps:
Connect the spark plug cap to the special
service tool.
Spark checker:
YM-34487
Ignition tester:
90890-06754
Crank the engine and observe the igni-
tion system spark through the discharge
window.
OK
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7-15
E
–+ELECIGNITION SYSTEM
IGNITION SYSTEM PEAK VOLTAGE
WARNING
When checking the electrical components,
do not touch any of the connections of the
digital tester lead wires.
NOTE:
If there is no spark, or the spark is weak,
continue with the ignition system test.
If a good spark is obtained, the problem is
not with the ignition system, but possibly with
the spark plug(s) or another component.
1. Measure:
ECM output peak voltage
Below specification →
Measure the
pickup coil output peak voltage.
NOTE:
When measuring the ECM output peak volt-
age while cranking the engine, disconnect
the ignition coil couplers for all cylinders
except for the cylinder being measured.
To crank the engine, connect the engine
shut-off cord (lanyard) to the engine shut-off
switch, and then press the start switch.
Test harness (2 pins):
New: YB-06867
Current: YB-06767
Test harness FWY-2 (2 pins):
New: 90890-06867
Current: 90890-06767
ECM output peak voltage:
Black/red (B/R) –
Red/yellow (R/Y)
Black/white (B/W) –
Red/yellow (R/Y)
Black/yellow (B/Y) –
Red/yellow (R/Y)
Black/green (B/G) –
Red/yellow (R/Y)
r/minLoaded
Cranking 2,000 3,500
V 90 130 140
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7-18
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–+ELEC
IGNITION COIL
1. Measure:
Primary coil resistance
Out of specification →
Replace.
NOTE:
When measuring a resistance of 10 Ω
or less
using a digital tester, the correct measurement
cannot be obtained because of the tester’s
internal resistance.
Refer to “Low resistance measurement”.
Primary coil resistance:
1.19–1.61
Ω at 20 °C (68 °F)
2. Measure:
Secondary coil resistance
Out of specification →
Replace.
Secondary coil resistance:
8.5–11.5 k
Ω at 20 °C (68 °F)
ENGINE STOP SWITCH
1. Check:
Engine stop switch continuity
Out of specification →
Replace.
Engine stop switch continuity
(black coupler)
Clip PositionLead color
White Black
InstalledFree
Push
RemovedFree
Push
IGNITION SYSTEM
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7-19
E
–+ELECIGNITION SYSTEM
ENGINE TEMPERATURE SENSOR
1. Measure:
Engine temperature sensor resistance
(at the specified temperature)
Out of specification →
Replace.
Engine temperature sensor
resistance:
20 °C (68 °F): 54.2–69.0 k
Ω
100 °C (212 °F): 3.12–3.48 k
Ω
Measurement steps:
Suspend the engine temperature sensor
in a container filled with water.
Place a thermometer in the water.
Slowly heat the water.
Measure the resistance when the speci-
fied temperature is reached.
SENSOR ASSEMBLY
1. Check:
Intake air temperature sensor
Out of specification →
Replace the sen-
sor assembly.
Checking steps:
Measure the ambient temperature.
Connect a computer to the watercraft and
use the Yamaha Diagnostic System to
display the intake air temperature.
If the ambient temperature and the dis-
played intake air temperature differ by
more than ±
5 °C (±
9 °F), replace the
sensor assembly.
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7-20
E
–+ELECIGNITION SYSTEM
THERMOSWITCH (ENGINE)
1. Check:
Thermoswitch (engine) continuity
(at the specified temperature)
Out of specification →
Replace.
1 No continuity
È Temperature
2 Continuity
É Time
NOTE:
The thermoswitch (engine) connector is blue.
Thermoswitch (engine) continuity
temperature:
a 84–90 °C (183–194 °F)
b 70–84 °C (158–183 °F)
Checking steps:
Suspend the thermoswitch (engine) in a
container filled with water.
Place a thermometer in the water.
Slowly heat the water.
Measure the continuity when the speci-
fied temperature is reached.
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7-47
E
–+ELECOFF THROTTLE STEERING SYSTEM
STEERING SENSOR
1. Check:
Steering sensor
Malfunction → Replace the steering
sensor.
Checking steps:
Turn the handlebar all the way to the left
or right, and then release it.
Install a plastic tie 1 loosely around the
center of the handlebar grip as shown.
Hook a spring gauge 2 onto the plastic
tie.
Hold the spring gauge at a 90° angle
from the handlebar, and then pull the
spring gauge with a force of 10 kgf
(22 lb).
When handlebar
pulledWhen handlebar
not pulled
ON OFF
Check that the following is displayed in
the “Engine Monitor” window of the
Yamaha Diagnostic System.
Use the same procedure to check that
the steering sensor operates correctly
when the handlebar is turned to both the
left and right. Replace the steering sen-
sor if it is a malfunction.
1
2
ECM
Refer to “IGNITION SYSTEM”.
PICKUP COIL
Refer to “IGNITION SYSTEM”.
THROTTLE POSITION SENSOR
Refer to “IGNITION SYSTEM”.
ACCELERATOR POSITION SENSOR
Refer to “IGNITION SYSTEM”.
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