2004 YAMAHA YZF-R1S Service Manual

8-16
YESNO
3. Starter motor

Connect the positive battery terminal and
starter motor lead with a jumper lead .
Repair or replace the
starter motor.
A wire that is used as a jumper lead
must have at least the same capacity or
more as that of the battery lead, other-
wise the jumper lead may burn.

This check is likely to produce sparks,
therefore make sure nothing flammable
is in the vicinity.

Does the starter motor turn?
WARNING
1
23
EAS00758
YESNO 2. Battery

Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
Minimum open-circuit voltage
12.8 V or more at 20C (68F)

Is the battery OK?

Clean the battery
terminals.

Recharge or re-
place the battery.
EAS00739
ELECTRIC STARTING SYSTEMELEC
NOTE:
YESNO
1. Main and ignition fuses

Check the main and ignition fuses for conti-
nuity.
Refer to “CHECKING THE FUSES” in chap-
ter 3.

Are the main and ignition fuses OK?
Replace the fuse(s).
EAS00757
TROUBLESHOOTING
The starter motor fails to turn.
Check:
1. main and ignition fuses
2. battery
3. starter motor
4. starting circuit cut-off relay
5. starter relay
6. main switch
7. engine stop switch
8. neutral switch
9. sidestand switch
10. clutch switch
11. start switch
12. wiring connections
(of the entire starting system)

Before troubleshooting, remove the following
part(s):
1. seat
2. fuel tank
3. side cowlings
4. throttle body assembly

Troubleshoot with the following special tool(s).
Pocket tester
90890-03112, YU-3112
EAS00738
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8-17
4. Starting circuit cut-off relay

Disconnect the starting circuit cut-off relay
coupler from the wire harness.

Connect the pocket tester (Ω
1) and bat-
tery (12 V) to the starting circuit cut-off relay
coupler as shown.
YESNO
Replace the starting
circuit cut-off relay.
Positive tester probe
blue / white
Negative tester probe
blue / white

Does the starting circuit cut-off relay have
continuity between blue / white and
blue / white ?
1
2
3
4
EAS00759
Positive battery terminal
red / black
Negative battery terminal

black / yellow
EAS00761
5. Starter relay

Disconnect the starter relay coupler from the
coupler.

Connect the pocket tester (Ω
1) and battery
(12 V) to the starter relay coupler as shown.
YESNO
Replace the starter
relay.
Positive battery terminal
blue / white
Negative battery terminal
red / white
Positive tester probe
red
Negative tester probe
black
1
2
3
4

Does the starter relay have continuity be-
tween red and black?
EAS00749
6. Main switch

Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the main switch OK?
YESNO
Replace the main
switch.
EAS00750
7. Engine stop switch

Check the engine stop switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the engine stop switch OK?
YESNO
Replace the right
handlebar switch.
EAS00751
8. Neutral switch

Check the neutral switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the neutral switch OK?
YESNO
Replace the neutral
switch.
3
4
ELECTRIC STARTING SYSTEMELEC
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8-18

Check the entire starting system’s wiring.
Refer to “CIRCUIT DIAGRAM”.

Is the starting system’s wiring properly con-
nected and without defects?
EAS00766
12. Wiring
YESNO
Properly connect or
repair the starting
system’s wiring.
The starting system
circuit is OK.
11. Start switch

Check the start switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the start switch OK?
YESNO
Replace the right
handlebar switch.
EAS00764
10. Clutch switch

Check the clutch switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the clutch switch OK?
YESNO
Replace the clutch
switch.
EAS00763EAS00752
9. Sidestand switch

Check the sidestand switch for continuity.
Refer to “CHECKING THE SWITCHES”.

Is the sidestand switch OK?
YESNO
Replace the side-
stand switch.
ELECTRIC STARTING SYSTEMELEC
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8-19
STARTER MOTORELEC
Order Job / Part Q’ty Remarks
1
2Removing the starter motor
Seat
Fuel tank
Throttle body assembly
Starter motor lead
Starter motor1
1Remove the parts in the order listed.
Refer to “SEAT” in chapter 3.
Refer to “FUEL TANK” in chapter 3.
Refer to “THROTTLE BODIES” in
chapter 7.
For installation, reverse the removal
procedure.
10 Nm (1.0 m
kg, 7.2 ft
lb)5 Nm (0.5 m
kg, 3.6 ft
lb)
5 Nm (0.5 m
kg, 3.6 ft
lb)
EAS00767
STARTER MOTOR
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8-20
STARTER MOTORELEC
Order Job / Part Q’ty Remarks
Disassembling the starter motor
O-ring
Front cover
Lock washer
Washer
Starter motor yoke
Armature assembly
O-ring
Starter motor lead
Brush holder
Rear cover1
1
1
1
1
1
2
2
1
1Disassemble the parts in the order listed.
For assembly, reverse the disassembly
procedure.
1
2
3
4
5
6
7
8
9
10
5 Nm (0.5 m
kg, 3.6 ft
lb)
5 Nm (0.5 m
kg, 3.6 ft
lb)
5 Nm (0.5 m
kg, 3.6 ft
lb)
EAS00768
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8-21
STARTER MOTORELEC
NOTE:
EAS00770
CHECKING THE STARTER MOTOR
1. Check:

commutator
Dirt
Clean with 600 grit sandpaper.
2. Measure:

commutator diameter
a
Out of specification
Replace the starter
motor.
Commutator wear limit
24.5 mm (0.96 in)
3. Measure:

mica undercut
a
Out of specification
Scrape the mica to the
proper measurement with a hacksaw blade
that has been grounded to fit the commuta-
tor.
Mica undercut
1.5 mm (0.06 in)
The mica of the commutator must be undercut
to ensure proper operation of the commutator.
4. Measure:

armature assembly resistances (commuta-
tor and insulation)
Out of specification
Replace the starter
motor.
a. Measure the armature assembly resistances
with the pocket tester.
Pocket tester
90890-03112, YU-3112
Armature coil
Commutator resistance
1
0.0090  0.0110 Ω
at 20C (68F)
Insulation resistance
2
Above 1 MΩ at 20C (68F)
b. If any resistance is out of specification, re-
place the starter motor.
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8-22
STARTER MOTORELEC
NOTE: 5. Measure:

brush length
a.
Out of specification
Replace the brushes
as a set.
Brush length wear limit
3.6 mm (0.14 in)
6. Measure:

brush spring force
Out of specification
Replace the brush
springs as a set.
Brush spring force
5.28  7.92 N
(538  808 gf, 18.99  28.48 oz)
7. Check:

gear teeth
Damage / wear
Replace the gear.
EAS00772
ASSEMBLING THE STARTER MOTOR
1. Install:

brush seat
1
Align the slot a on the brush seat with the tab b
in the starter motor rear cover.
2. Install:

armature
1
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8-23
STARTER MOTORELEC
5 Nm (0.5 m
kg, 3.6 ft
lb)
NOTE: 3. Install:

starter motor yoke
1

O-rings 2 New

starter motor rear cover
3

bolts
Align the match marks
a on the starter motor
yoke with the match marks
b on the front and
rear covers.
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