Yamaha YFM660 01 User Manual

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–+ELECIGNITION SYSTEM
C0NTINUITY
MEETS
SPECIFICATION 10.Charging/rotor rotation direction detec-
tion 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 1 
Tester (–) lead → White/Blue terminal 2 

Check the charging/rotor rotation direction
detection coil for the specified resistance.
Rotor rotation direction detec-
tion coil resistance:
0.069 ~ 0.085 Ω at 20 °C (68 °F)
(Red – White/Blue)
*
OUT OF SPECIFICATION
Replace the pickup coil/stator assembly.
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. 
						

							8 - 11
–+ELECELECTRIC STARTING SYSTEM
EB803000
ELECTRIC STARTING SYSTEM
CIRCUIT DIAGRAM
3Main switch
4Battery
5Fuse
6Starter relay
7Starter motor
8Clutch switch
9Park switch
0CDI unit
JNeutral switch
PEngine stop switch
QStart switch 
						

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–+ELECELECTRIC STARTING SYSTEM
STARTING CIRCUIT OPERATION
The starting circuit on this model consists of
the starter motor, starter relay, clutch switch,
CDI unit and neutral switch. If the main switch
is on and the engine stop switch is in the RUN
position, the starter motor can be operated
only if: 
1Fuse
2Battery
3Starter relay
4Starter motor
5Start switch
6CDI unit
7Engine stop switch
8Neutral switch
9Clutch switch
ÈTO MAIN SWITCH
ÉFROM MAIN SWITCH

The transmission is in neutral (the neutral
switch is closed).
or

You pull in the clutch lever (the clutch
switch is closed). 
						

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–+ELECELECTRIC STARTING SYSTEM
EB803020
TROUBLESHOOTING
Procedure
Check:
1.Fuse
2.Battery
3.Starter motor
4.Starter relay
5.Main switch
6.Engine stop switchIF THE STARTER MOTOR FAILS TO OPERATE:
7.Start switch
8.Neutral switch
9.Clutch switch
10.Wiring connection (the entire starting sys-
tem)
OTE:

Remove the following part(s) before trouble-
shooting:
1)Seat
2)Front fender
3)Rear fender
4)Exhaust pipe

Use the following special tool(s) for trouble-
shooting.
Pocket tester:
P/N. YU-03112, 90890-03112
EB802011
CONTINUITY 1.Fuse
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. 
						

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–+ELECELECTRIC STARTING SYSTEM
C0NTINUITY
 
TURNS 3.Starter motor

Connect the battery positive terminal 1
and starter motor cable 2
 using a jumper
lead 3
 .

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 har-
ness.

Connect the pocket tester (Ω
 ×
 1) and the
battery (12 V) to the starter relay terminals.
CONTINUITY Battery (+) terminal → 
Yellow/Black terminal 1
Battery (–) terminal → 
Blue/Black terminal 2
Tester (+) lead → Red terminal 3 
Tester (–) lead → Black terminal 4 

Check the starter relay for continuity.
NO CONTINUITY 
Replace the starter relay.
CORRECT 5.Main switch
Refer to “CHECKING THE SWITCH”.
*
INCORRECT 
Replace the main switch. 
						

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–+ELECELECTRIC STARTING SYSTEM
C0NTINUITY
CORRECT 6.Engine stop switch
Refer to “CHECKING THE SWITCH”.
*
INCORRECT
Replace the handlebar switch (right).
CORRECT 7.Start switch
Refer to “CHECKING THE SWITCH”.
INCORRECT 
Replace the handlebar switch (left).
CORRECT 8.Neutral switch
Refer to “CHECKING THE SWITCH”.
INCORRECT
Replace the neutral switch.
CORRECT 9.Clutch switch
Refer to “CHECKING THE SWITCH”.
INCORRECT
Replace the clutch switch.
EB803028
10.Wiring connection

Check the connections of the entire starting
system.
Refer to “CIRCUIT DIAGRAM”.
POOR CONNECTION
Properly connect the starting system. 
						

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–+ELECELECTRIC STARTING SYSTEM
STARTER MOTOR
Order Job name/Part name Q’ty Remarks
Removing the starter motor
Remove the parts in the order below.
Exhaust pipe Refer to “ENGINE REMOVAL”.
1 Parking brake cable 1 Disconnect.
2 Starter motor lead 1
3Starter motor/O-ring1/1
Disassembling the starter motor
Remove the parts in the order below.
1
  Starter motor drive gear 1
2
 Bracket 1 1
Refer to “ASSEMBLING THE STARTER 
MOTOR”. 3
 Washer kit
4
 Bracket 2 1
5
 Shims
6
  Brush seat 1/brush seat 2 1/1
7
 Armature coil 1
8
 Yoke 1
For assembly, reverse the disassembly 
procedure. 
						

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–+ELECELECTRIC STARTING SYSTEM
CHECKING THE STARTER MOTOR
1.Check:

Commutator
Dirty →
 Clean it with #600 grit sandpaper.
2.Measure:

Commutator diameter a
 
Out of specification →
 Replace the starter
motor. 
3.Measure:

Mica undercut b
 
Out of specification →
 Scrape the mica using
a hacksaw blade. 
OTE:
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)

27 mm (1.06 in)
Mica undercut:
0.7 mm (0.03 in)
4.Check:

Armature coil (insulation/continuity)
Defects →
 Replace the starter motor.
***********************************************
Armature coil checking steps:

Connect the pocket tester for the continuity
check 1
 and insulation check 2
.

Measure the armature resistances. 

If the resistance is incorrect, replace the
starter motor.
***********************************************
Armature coil resistance:
Continuity check 1:
0.025 ~ 0.035 Ω at 20 °C (68 °F)
Insulation check 2:
More than 1 MΩ at 20 °C (68 °F) 
						

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–+ELECELECTRIC STARTING SYSTEM
5.Measure:

Brush length a
 (each)
Out of specification →
 Replace the brush. 
Brush length:
12.5 mm (0.49 in)

5 mm (0.20 in)
6.Measure:

Brush spring force
Fatigue/out of specification →
 Replace as a
set. 
Brush spring force:
7.65 ~ 10.01 Nm
(27.5 ~ 36.0 oz)
7.Check:

Oil seal

Bushing

O-rings
Wear/damage →
 Replace.
ASSEMBLING THE STARTER MOTOR
1.Install:

Brush seat 1
 
OTE:
Align the projection a
 on the brush seat with
the slot b
 on the housing.
2.Install:

Yoke 

Brackets
OTE:
Align the match marks a
 on the yoke with the
match marks b
 on the brackets. 
						

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–+ELECCHARGING SYSTEM
EB804000
CHARGING SYSTEM
CIRCUIT DIAGRAM 
1AC magneto
2Rectifier/regulator
4Battery
5Fuse