Content .. 20 21 22 23 ..

Yamaha YFM45FAR, YFM450FAR. Service Manual - part 22

9 - 5

–

ELEC

CHECKING THE SWITCH

Light switch

Engine stop switch

Start switch

On-command four-wheel drive switch and differential gear lock switch

Main switch

Rear brake light switch

Front brake light switch

Rear brake switch

Horn switch (for Europe and Oceania)

Reverse switch

Neutral switch

High-range switch

Low-range switch

Fuse

9 - 6

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ELEC

CHECKING THE BULBS AND BULB SOCKETS

EB801020

CHECKING THE BULBS AND
BULB SOCKETS

Check each bulb and bulb socket for damage
or wear, proper connections, and also for
continuity between the terminals.

Damage/wear

→

Repair or replace the bulb,

bulb socket or both.
Improperly connected

→

Properly connect.

Incorrect continuity reading

→

Repair or

replace the bulb, bulb socket or both.

TYPES OF BULBS

The bulbs used on this machine are shown in
the illustration on the left.

●

Bulbs

and

are used for headlights and

usually use a bulb holder which must be
detached before removing the bulb. The
majority of these bulbs can be removed from
their respective socket by turning them
counterclockwise.

●

Bulb

is used for turn signal and brake/tail

lights and can be removed from the socket
by pushing and turning the bulb
counterclockwise.

●

Bulbs

and

are used for meter and

indicator lights and can be removed from
their respective socket by carefully pulling
them out.

CHECKING THE CONDITION OF THE
BULBS

The following procedure applies to all of the
bulbs.
1.Remove:

●

Bulb

9 - 7

–

ELEC

CHECKING THE BULBS AND BULB SOCKETS

WARNING

Since the headlight bulb gets extremely
hot, keep flammable products and your
hands away from the bulb until it has
cooled down.

CAUTION:

●

Be sure to hold the socket firmly when
removing the bulb. Never pull the lead,
otherwise it may be pulled out of the
terminal in the coupler.

●

Avoid touching the glass part of the
headlight bulb to keep it free from oil,
otherwise the transparency of the glass,
the life of the bulb and the luminous flux
will be adversely affected. If the headlight
bulb gets soiled, thoroughly clean it with
a cloth moistened with alcohol or lacquer
thinner.

2.Check:

●

Bulb (for continuity)
(with the pocket tester)
No continuity

→

Replace.

NOTE:

Before checking for continuity, set the pocket
tester to “0” and to the “

Ω

1” range.

*****************************************************
a.Connect the tester positive probe to terminal

and the tester negative probe to terminal

, and check the continuity.

b.Connect the tester positive probe to terminal

and the tester negative probe to terminal

, and check the continuity.

c.If either of the readings indicate no

continuity, replace the bulb.

*****************************************************

Pocket tester

P/N. YU-03112, 90890-03112

9 - 8

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ELEC

CHECKING THE CONDITION OF THE BULB
SOCKETS

The following procedure applies to all of the
bulb sockets.
1.Check:

●

Bulb socket (for continuity)
(with the pocket tester)
No continuity

→

Replace.

NOTE:

Check each bulb socket for continuity in the
same manner as described in the bulb section;
however, note the following.

*****************************************************
a.Install a good bulb into the bulb socket.
b.Connect the pocket tester probes to the

respective leads of the bulb socket.

c.Check the bulb socket for continuity. If any of

the readings indicate no continuity, replace
the bulb socket.

*****************************************************

Pocket tester:

P/N. YU-03112, 90890-03112

CHECKING THE BULBS AND BULB SOCKETS

9 - 9

–

ELEC

IGNITION SYSTEM

EB802000

IGNITION SYSTEM

CIRCUIT DIAGRAM

(GRA

WIRE HARNESS

SUB-WIRE

HARNESS 4

(BLA

CK)

(BLA

CK)

(BLA

CK)

WIRE HARNESS

SUB-WIRE

HARNESS 3

WIRE HARNESS

SUB-WIRE

HARNESS 2

WIRE HARNESS

SUB-WIRE

HARNESS 1

(BLA

CK)

(BLA

CK)

(BLA

CK)

(GRA

(BLA

CK)

(BLA

CK)

(GRA

OFF

2WD

4WD

LOCK

PUSH

(BLACK)

G
Y

PUSH

(BLACK)

G
Y

L
Y

(DARK GRAY)

(BLACK)

]

[

A.C.

agn

Main s

witc

Battery

Main

CDI

unit

Rear

bra

e swit

Ignit

ion

Spar

k p

lug

Ignit

ion

ine

witch

9 - 10

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ELEC

IGNITION SYSTEM

EB802010

TROUBLESHOOTING

Procedure

Check:
1.Fuse (main, ignition)
2.Battery
3.Spark plug
4.Ignition spark gap
5.Spark plug cap resistance
6.Ignition coil resistance

IF THE IGNITION SYSTEM FAILS TO OPERATE (NO SPARK OR INTERMITTENT SPARK):

7.Engine stop switch
8.Main switch
9.Pickup coil resistance

10.Charging/rotor rotation direction detection

coil resistance

11.Wiring connection (the entire ignition

system)

NOTE:

●

Remove the following part(s) before
troubleshooting:

1)Seat
2)Fuel tank side panels
3)Front carrier
4)Front fender

●

Use the following special tool(s) for
troubleshooting.

Dynamic spark tester:

P/N. YM-34487

Ignition checker:

P/N. 90890-06754

Pocket tester:

P/N. YU-03112, 90890-03112

EB802011

CONTINUITY

1.Fuse (main, ignition)

Refer to “CHECKING THE SWITCH”.

NO CONTINUITY

Replace the fuse.

EB802012

CORRECT

2.Battery

●

Check the battery condition.
Refer to “CHECKING THE BATTERY” in
CHAPTER 3.

Open-circuit voltage:

12.8 V or more at 20 °C (68 °F)

INCORRECT

●

Clean the battery terminals.

●

Recharge or replace the battery.

3.Spark plug

●

Check the spark plug condition.

●

Check the spark plug type.

●

Check the spark plug gap.
Refer to “CHECKING THE SPARK PLUG”
in CHAPTER 3.

Standard spark plug:

DR8EA/NGK

9 - 11

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ELEC

IGNITION SYSTEM

CORRECT

Spark plug gap:

0.6 ~ 0.7 mm (0.024 ~ 0.028 in)

INCORRECT

Repair or replace the spark plug.

For CDN

4.Ignition spark gap

●

Disconnect the spark plug cap from the
spark plug.

●

Connect the dynamic spark tester

shown.

Spark plug cap

Spark plug

●

Turn the main switch to “ON”.

●

Check the ignition spark gap.

●

Crank the engine by pushing the starter
switch, and increase the spark gap until a
misfiring occurs.

Minimum spark gap:

6.0 mm (0.24 in)

MEETS SPECIFICATION

The ignition system is not faulty.

5.Spark plug cap resistance

●

Remove the spark plug cap.

●

Connect the pocket tester (

Ω

1k) to the

spark plug cap.

For Europe and Oceania

OUT OF
SPECIFICATION
OR NO SPARK

4.Ignition spark gap

●

Disconnect the spark plug cap from the
spark plug.

●

Connect the ignition checker

as shown.

Spark plug cap

●

Turn the main switch to “ON”.

●

Check the ignition spark gap

●

Crank the engine by pushing the starter
switch, and increase the spark gap until a
misfiring occurs.

Minimum spark gap:

6.0 mm (0.24 in)

MEETS SPECIFICATION

The ignition system is not faulty.

9 - 12

–

ELEC

IGNITION SYSTEM

6.Ignition coil resistance

●

Disconnect the ignition coil connector from
the wire harness.

●

Connect the pocket tester (

Ω

1) to the

ignition coil.

Tester (+) lead

→

Orange lead terminal

Tester (–) lead

→

Ignition coil base

●

Check that the primary coil has the
specified resistance.

Primary coil resistance:

0.18 ~ 0.28

Ω

at 20 °C (68 °F)

BOTH MEET
SPECIFICATION

●

Connect the pocket tester (

Ω

1k) to the

ignition coil.

Tester (+) lead

→

Orange lead terminal

Tester (–) lead

→

Spark plug lead

●

Check that the secondary coil has the
specified resistance.

Secondary coil resistance:

6.32 ~ 9.48 k

Ω

at 20 °C (68 °F)

OUT OF SPECIFICATION

Replace the ignition coil.

CORRECT

7.Engine stop switch

Refer to “CHECKING THE SWITCH”.

INCORRECT

Replace the handlebar switch (left).

MEETS
SPECIFICATION

●

Check that the spark plug cap has the
specified resistance.

Spark plug cap resistance:

10 k

Ω

at 20 °C (68 °F)

OUT OF SPECIFICATION

Replace the spark plug cap.

9 - 13

–

ELEC

IGNITION SYSTEM

C0NTINUITY

CORRECT

8.Main switch

Refer to “CHECKING THE SWITCH”.

INCORRECT

Replace the main switch.

9.Pickup coil resistance

●

Disconnect the AC magneto coupler from
the wire harness.

●

Connect the pocket tester (

Ω

100) to the

pickup coil terminal.

Tester (+) lead

→

White/Red terminal

Tester (–) lead

→

White/Green terminal

MEETS
SPECIFICATION

●

Check the pickup coil for the specified
resistance.

Pickup coil resistance:

459 ~ 561

Ω

at 20 °C (68 °F)

(White/Red – White/Green)

OUT OF SPECIFICATION

Replace the pickup coil/stator assembly.

10.Charging/rotor rotation direction detection

coil resistance

●

Disconnect the AC magneto coupler from
the wire harness.

●

Connect the pocket tester (

Ω

100) to the

charging/rotor rotation direction detection
coil terminal.

Tester (+) lead

→

Red terminal

Tester (–) lead

→

White/Blue terminal

MEETS
SPECIFICATION

●

Check the charging/rotor rotation direction
detection coil for the specified resistance.

Rotor rotation direction sensing
coil resistance:

0.085 ~ 0.105

Ω

at 20 °C (68 °F)

(Red – White/Blue)

OUT OF SPECIFICATION

Replace the pickup coil/stator assembly.

9 - 14

–

ELEC

IGNITION SYSTEM

C0NTINUITY

CORRECT

11.Wiring connection

●

Check the connections of the entire ignition
system.
Refer to “CIRCUIT DIAGRAM”.

Replace the CDI unit.

POOR CONNECTION

Properly connect the ignition system.

9 - 15

–

ELEC

ELECTRIC STARTING SYSTEM

EB803000

ELECTRIC STARTING SYSTEM

CIRCUIT DIAGRAM

(GRA

WIRE HARNESS

SUB-WIRE

HARNESS 4

(BLA

CK)

(BLA

CK)

(BLA

CK)

WIRE HARNESS

SUB-WIRE

HARNESS 3

WIRE HARNESS

SUB-WIRE

HARNESS 2

WIRE HARNESS

SUB-WIRE

HARNESS 1

(BLA

CK)

(BLA

CK)

(BLA

CK)

(GRA

(BLA

CK)

(BLA

CK)

(GRA

OFF

2WD

4WD

LOCK

PUSH

(BLACK)

G
Y

PUSH

(BLACK)

G
Y

L
Y

(DARK GRAY)

(BLACK)

]

[

Main switch

Main

rte

r re

lay

rte

r mo

I u

nit

ion f

gin

swit

tart switc

9 - 16

–

ELEC

ELECTRIC STARTING SYSTEM

EB803020

TROUBLESHOOTING

Procedure

Check:
1.Fuse (main, ignition)
2.Battery
3.Starter motor
4.Starter relay
5.Main switch

IF THE STARTER MOTOR FAILS TO OPERATE:

6.Engine stop switch
7.Start switch
8. Wiring connection (the entire starting

system)

NOTE:

●

Remove the following part(s) before
troubleshooting:

1)Seat
2)Fuel tank side panels
3)Fuel tank
4)Air cleaner case
5)Front carrier
6)Front fender panel

●

Use the following special tool(s) for
troubleshooting.

Pocket tester:

P/N. YU-03112, 90890-03112

EB802011

CONTINUITY

1.Fuse (main, ignition)

Refer to “CHECKING THE SWITCH”.

NO CONTINUITY

Replace the fuse.

EB802012

CORRECT

2.Battery

●

Check the battery condition.
Refer to “CHECKING THE BATTERY” in
CHAPTER 3.

Open-circuit voltage:

12.8 V or more at 20 °C (68 °F)

INCORRECT

●

Clean the battery terminals.

●

Recharge or replace the battery.

9 - 17

–

ELEC

ELECTRIC STARTING SYSTEM

C0NTINUITY

TURNS

3.Starter motor

●

Connect the battery positive terminal

and starter motor cable

using a jumper

lead

●

Check the operation of the starter motor.

WARNING

●

A wire that is used as a jumper lead must
have the equivalent capacity or more as
that of the battery lead, otherwise the
jumper lead may burn.

●

This check is likely to produce sparks, so
be sure that no flammable gas or fluid is
in the vicinity.

DOES NOT TURN

Repair or replace the starter motor.

4.Starter relay

●

Remove the starter relay from the wire
harness.

●

Connect the pocket tester (

Ω

1) and the

battery (12 V) to the starter relay terminals.

CONTINUITY

Battery (+) terminal

→

Blue/White terminal

Battery (–) terminal

→

Blue/Black terminal

Tester (+) lead

→

Red terminal

Tester (–) lead

→

Black terminal

●

Check the starter relay for continuity.

NO CONTINUITY

Replace the starter relay.

9 - 18

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ELEC

ELECTRIC STARTING SYSTEM

C0NTINUITY

CORRECT

5.Main switch

Refer to “CHECKING THE SWITCH”.

INCORRECT

Replace the main switch.

CORRECT

6.Engine stop switch

Refer to “CHECKING THE SWITCH”.

INCORRECT

Replace the handlebar switch (left).

CORRECT

7.Start switch

Refer to “CHECKING THE SWITCH”.

INCORRECT

Replace the handlebar switch (left).

EB803028

8.Wiring connection

●

Check the connections of the entire starting
system.
Refer to “CIRCUIT DIAGRAM”.

POOR CONNECTION

Properly connect the starting system.

9 - 19

–

ELEC

ELECTRIC STARTING SYSTEM

STARTER MOTOR

Order

Job name/Part name

Q’ty

Remarks

Removing the starter motor

Remove the parts in the order below.

Starter motor lead

Starter motor/O-ring

1/1

Disassembling the starter motor

Remove the parts in the order below.

Bracket

Refer to “ASSEMBLING THE STARTER
MOTOR”.

Washer

kit

Bracket

2/bushing

Shims

Brush holder set

Armature

coil

Yoke

For assembly, reverse the disassembly
procedure.

9 - 20

–

ELEC

ELECTRIC STARTING SYSTEM

CHECKING THE STARTER MOTOR

1.Check:

●

Commutator
Dirty

→

Clean it with #600 grit sandpaper.

2.Measure:

●

Commutator diameter

Out of specification

→

Replace the starter

motor.

3.Measure:

●

Mica undercut

Out of specification

→

Scrape the mica using

a hacksaw blade.

NOTE:

Scrape the mica to the proper measurement
using a hacksaw blade which has been
grounded to fit the commutator.

Outside diameter:

28 mm (1.10 in)

<Wear limit:>

27 mm (1.06 in)

Mica undercut:

0.7 mm (0.03 in)

4.Check:

●

Armature coil (insulation/continuity)
Defects

→

Replace the starter motor.

*****************************************************

Checking steps:

●

Connect the pocket tester for the continuity
check

and insulation check

●

Measure the armature resistances.

●

If the resistance is incorrect, replace the
starter motor.

*****************************************************

Armature coil resistance:

Continuity check

0.025 ~ 0.035

Ω

at 20 °C (68 °F)

Insulation check

More than 1 M

Ω

at 20 °C (68 °F)

Content .. 20 21 22 23 ..