YAMAHA WR 250F 2015 Owners Manual

OIL PUMP AND BALANCER GEAR
6-60
NOTICE
After tightening the bolts, make sure that
the oil pump turns smoothly.
2. Install:
• Collar “1”
• Balancer weight gear “2”
TIP
Install the balancer weight gear and balancer
shaft with their lower splines “a” aligning with
each other.
3. Install:
• Balancer drive gear “1”
• Collar “2”
TIP
• Align the punched mark “a” on the balancer
drive gear with the punched mark “b” on the
balancer weight gear.
• Install the balancer drive gear and crankshaft
with the lower splines “c” aligning with each
other.4. Install:
• Conical washer “1”
• Balancer weight gear nut “2”
• Primary drive gear “3”
• Conical washer “4”
• Primary drive gear nut “5”
•Balancer “6”
• Conical washer “7”
• Balancer nut “8”
TIP
• Apply engine oil to the contact surface and
threaded portion of the primary drive gear nut.
• Place an aluminum plate “a” between the
teeth of the balancer drive gear “9” and bal-
ancer weight gear “10”.
• Install the conical washer with its convex sur-
face “b” outward.
• Align the balancer flat portion “c” with the flat
portion “d”.
21
1
2
Balancer weight gear nut
50 Nm (5.0 m·kgf, 36 ft·lbf)
Primary drive gear nut
75 Nm (7.5 m·kgf, 54 ft·lbf)
Balancer nut
38 Nm (3.8 m·kgf, 27 ft·lbf)
New
T R..
New
T R..
New
T R..
a
210
b
2 91
b53
a41059
3
E

OIL PUMP AND BALANCER GEAR
6-61
c
d
6 6
78
8 b

GENERATOR AND STARTER CLUTCH
6-62
EAS2GB2307
GENERATOR AND STARTER CLUTCH
Removing the generator
Order Job/Parts to remove Q’ty Remarks
Drain the engine oil.Refer to “CHANGING THE ENGINE OIL” on
page 3-17.
Seat and fuel tankRefer to “GENERAL CHASSIS” on page 5-1
and “FUEL TANK” on page 8-1.
Disconnect the AC magneto lead.
Clutch cable
Shift pedal Refer to “SHIFT SHAFT” on page 6-52.
1 Cover (Damper assembly) 1
2 Damper assembly 1
3 Breather hose 1
4 Left crankcase cover 1
5Gasket 1
6 Dowel pin 2
7 Starter idle gear 1
8 Bearing 1
9 Starter idle gear shaft 1
10 Generator rotor 1
T R..
T R..
6
611
9
8
7
2
3
1
14
4 5
12
10
13
T R..
T R..
T R..LTT R..
T R..
15

GENERATOR AND STARTER CLUTCH
6-63
11 Woodruff key 1
12 Starter clutch 1
13 Starter clutch drive gear 1
14 Crankshaft position sensor 1
15 Stator 1
For installation, reverse the removal proce-
dure.
Removing the generator
Order Job/Parts to remove Q’ty Remarks
T R..
T R..
6
611
9
8
7
2
3
1
14
4 5
12
10
13
T R..
T R..
T R..LTT R..
T R..
15

GENERATOR AND STARTER CLUTCH
6-64
EAS2GB2308REMOVING THE GENERATOR
1. Remove:
• Generator rotor nut “1”
• Washer
2. Remove:
• Generator rotor “1”
(with the rotor puller “2”)
• Woodruff key
EAS2GB2309CHECKING THE STARTER CLUTCH
1. Check:
• Starter clutch rollers
Damage/wear  Replace.
2. Check:
• Starter clutch idle gear
• Starter clutch gear
Burrs/chips/roughness/wear  Replace the
defective part (s).3. Check:
• Starter clutch gear
Damage/pitting/wear  Replace the starter
clutch gear.
4. Check:
• Damper assembly
Damage/pitting/wear  Replace the damp-
er assembly.
Check the gear of the starter motor arma-
ture.
5. Check:
• Starter clutch operation
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Install the starter clutch drive gear “1” onto
the starter clutch and hold the starter clutch.
b. When turning the starter clutch drive gear
clockwise “A”, the starter clutch and the
starter clutch drive gear should engage, oth-
erwise the starter clutch is faulty and must
be replaced.
c. When turning the starter clutch drive gear
counterclockwise “B”, it should turn freely,
otherwise the starter clutch is faulty and
must be replaced.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
Rotor puller
90890-04142
Rotor puller
YM-04142
1
1
2
1 A
B

GENERATOR AND STARTER CLUTCH
6-65
EAS2GB2310INSTALLING THE STARTER CLUTCH
1. Install:
• Stator “1”
• Stator bolt “2”
• Crankshaft position sensor “3”
• Holder “4”
• Crankshaft position sensor bolt “5”
TIP
• Pass the AC magneto lead “6” and crankshaft
position sensor lead “7” under the holder as
shown.
• Tighten the stator bolt using the T25 bit.
• Apply the sealant to the grommet of the AC
magneto lead.
2. Install
• Starter clutch drive gear “1”
TIP
Apply the engine oil on the starter clutch drive
gear inner circumference.3. Install:
• Starter clutch “1”
To generator rotor “2”.
EAS2GB2311INSTALLING THE GENERATOR
1. Install:
• Woodruff key “1”
• Generator rotor “2”
TIP
• Clean the contact surfaces of the tapered por-
tions of the crankshaft and generator rotor.
• When installing the woodruff key, make sure
that its flat surface “a” is in parallel with the
crankshaft center line “b”.
• When installing the generator rotor, align the
keyway “c” of the generator rotor with the
woodruff key. Stator bolt
7 Nm (0.7 m·kgf, 5.1 ft·lbf)
LOCTITE®
Crankshaft position sensor bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Yamaha bond No. 1215
90890-85505
(Three bond No.1215®)
T R..
T R..
6
7
1
3
22
5
5
4LT
Starter clutch bolt
16 Nm (1.6 m·kgf, 12 ft·lbf)
LOCTITE®
21
LT
T R..
2 C1 1
1a b

GENERATOR AND STARTER CLUTCH
6-66
2. Install:
• Washer
• Generator rotor nut “1”
TIP
Tighten the generator rotor nut to 65 Nm (6.5
m·kgf, 47 ft·lbf), loosen and retighten the gener-
ator rotor nut to 65 Nm (6.5 m·kgf, 47 ft·lbf).
3. Install:
• Starter idle gear shaft “1”
• Bearing “2”
• Starter idle gear 2 “3”
TIP
Apply the engine oil on the starter idle gear
shaft, bearing and idle gear inner circumfer-
ence.
4. Install:
• Dowel pin
• Crankcase cover gasket
• Left crankcase cover “1”
• Lead holder “2”
• Crankcase cover bolt
• Neutral switch lead “3”
TIP
• Pass the AC magneto lead “4” under the left
crankcase cover “a” as shown.
• Tighten the bolts in stage, using a crisscross
pattern.
5. Install:
• Washer “1”
• Damper assembly “2”
• Washer “3”
TIP
Apply the engine oil to the shaft and washers.
6. Install:
• Cover (damper assembly) “1”
• Bracket “2”
•Bolt “3”
• Breather hose 2 “4” Generator rotor nut
65 Nm (6.5 m·kgf, 47 ft·lbf)
Crankcase cover bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
T R..
1
1
21
2
3
New
T R..Bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
4
1a
1
2
3
21
2
3
T R..

GENERATOR AND STARTER CLUTCH
6-67
TIP
Install the cover (damper assembly) with its
mark “a” facing upward.
1a3
3
2
4

CRANKCASE
6-68
EAS2GB2312
CRANKCASE
Separating the crankcase
Order Part name Q’ty Remarks
Engine Refer to “ENGINE REMOVAL” on page 6-1.
PistonRefer to “CYLINDER AND PISTON” on page
6-30.
BalancerRefer to “OIL PUMP AND BALANCER
GEAR” on page 6-56.
Kick shaft assembly Refer to “KICKSTATER” on page 6-49.
Segment Refer to “SHIFT SHAFT” on page 6-52.
Generator rotorRefer to “GENERATOR AND STARTER
CLUTCH” on page 6-62.
1 Timing chain guide (exhaust side) 1
2 Timing chain guide stopper plate 1
3 Timing chain 1
4 Bolt [L = 45 mm (1.77 in)] 7
5 Bolt [L = 60 mm (2.36 in)] 2
6 Bolt [L = 75 mm (2.95 in)] 3
7 Right crankcase 1
8 Left crankcase 1
9 Dowel pin 2
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R
.
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R
.
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R
.
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R
.
3
1 5
2
6410 56
4
4
446
9117
8
9
LT

CRANKCASE
6-69
10 Crankshaft 1
11 Oil passage squeeze nozzle 1
For assembly, reverse the disassemble pro-
cedure.
Separating the crankcase
Order Part name Q’ty Remarks
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R
.
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R
.
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R
.
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R.
3
1 5
2
6410 56
4
4
446
9117
8
9
LT