Yamaha WaveRunner VXR VX1800A, Service Manual

Page: 218 / 318

7-11
Ignition system
Ignition system
Ignition spark check
When performing the spark gap check,
keep flammable gas or liquids away, since
this test can produce sparks.
1. Connect the YDIS.
2. Remove the ignition coil for the cylinder
that will be tested.
3. Connect the ignition coil to the special ser-
vice tool “1”.
4. Using the “Stationary test” of the YDIS,
check the ignition spark.
Do not touch any of the connections of the
special service tool leads.
5. Disconnect the special service tool, and
then install the ignition coil.
Ignition coil check
1. Disconnect the ignition coil couplers “a”.
2. Supply power to the ECM, and then mea-
sure the input voltage at the ignition coil
coupler terminals (wire harness end).
Check the wire harness if out of specifica-
tion. Check the ECM output peak voltage if
within specification.
3. Connect the test harness. See “Test lead
preparation” (7-10).
4. Measure the ECM output peak voltage.
When checking the electrical components,
do not touch any of the connections of the
digital tester leads.
TIP:
• When measuring the ECM output peak volt-
age under the “Cranking” condition, discon-
nect the fuel injector couplers for all
cylinders.
• To crank the engine, connect the engine
shut-off cord (lanyard) to the engine shut-off
switch, and then push the engine start
switch.
• When measuring the ECM output peak volt-
age, use only a properly functioning ignition
coil. If the ignition coil is not functioning prop-
erly, ECM output peak voltage will not be
generated.
Ignition checker (Spark gap tester) “1”
90890-06754
Spark checker “1”
YM-34487
1
Input voltage
12 V (battery voltage)
Red/Yellow (R/Y)–Black (B)
a
B R/Y