2016 YAMAHA WR 250F engine

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..

CRANKCASE
6-68
EAS2GB7310
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
6-71
EAS2GB7311DISASSEMBLING THE CRANKCASE
1. Separate:
• Right crankcase
• Left crankcase
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the crankcase bolts.
TIP
Loosen each bolt 1/4 of a turn at a time and af-
ter all the bolts are loosened, remove them.
b. Remove the right crankcase “1”.
TIP
• Place the crankcase with its left side down-
ward and split it by inserting a screwdriver tip
into the splitting slit “a” in the crankcase.
• Lift the right crankcase horizontally while light-
ly patting the crankcase splitting slit and the
engine mounting boss using a soft hammer,
and leave the crankshaft and the transmission
with the left crankcase.
ECA
NOTICE
Use soft hammer to tap on the case half.
Tap only on reinforced portions of case. Do
not tap on gasket mating surface. Work
slowly and carefully. Make sure the case
halves separate evenly. If the cases do not
separate, check for a remaining case bolt or
fitting. Do not force.c. Remove the dowel pins and O-ring.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GB7312REMOVING THE CRANKCASE BEARING
1. Remove:
• Bearing “1”
TIP
• Remove the bearing from the crankcase by
pressing its inner race.
• Do not use the removed bearing.
EAS2GB7313CHECKING THE TIMING CHAIN, TIMING
CHAIN GUIDE, OIL STRAINER
1. Check:
• Timing chain
Stiffness  Replace the camshaft sprocket,
timing chain and crankshaft sprocket as a
set.
2. Check:
• Timing chain guide
Damage/wear  Replace
EAS2GB7314CHECKING THE CRANKCASE
1. Wash:
• Crankcase
TIP
• Wash the crankcase in a mild solvent.
• Remove any remaining gasket from the
crankcase mating surface.
2. Check:
• Crankcase
Crack/damage  Replace.
1
a

TRANSMISSION
6-76
EAS2GB7322
TRANSMISSION
Removing the transmission, shift drum assembly, and shift forks
Order Part name Q’ty Remarks
Engine Refer to “ENGINE REMOVAL” on page 6-1.
CrankcaseSeparate.
Refer to “CRANKCASE” on page 6-68.
1 Main axle 1
2 Drive axle 1
3 Long shift fork guide bar 1
4 Short shift fork guide bar 1
5Spring 4
6 Shift cam 1
7 Shift fork 3 (R) 1
8 Shift fork 2 (C) 1
9 Shift fork 1 (L) 1
10 Collar 1
For installation, reverse the removal proce-
dure.
2
10
1
53
4 578
69
M
M
M
M
M
EE
E
E
LS
New

TRANSMISSION
6-79
2. Install:
• 2nd wheel gear (29T) “1”
• 5th wheel gear (22T) “2”
• 3rd wheel gear (26T) “3”
• 4th wheel gear (24T) “4”
• 6th wheel gear (22T) “5”
• Collar “6”
• 1st wheel gear (31T) “7”
• O-ring “8”
(to the drive axle “9”)
TIP
• Before installation, apply molybdenum disul-
fide oil to the inner and end surface of the idler
gear and to the inner surface of the sliding
gear, then install.
• Apply the lithium-soap-based grease on the
O-ring.
3. Install:
• Washer “1”
• Circlip “2”
TIP
• Be sure the circlip sharp-edged corner “a” is
positioned opposite side to the washer and
gear “b”.
• Install the circlip with its ends “c” settled even-
ly on the spline crests.4. Install:
• Collar “1”
TIP
• Apply the lithium-soap-based grease on the
oil seal lip.
• When installing the collar into the crankcase,
pay careful attention to the crankcase oil seal
lip.
5. Install:
• Main axle “1”
• Drive axle “2”
TIP
• Install to the left crankcase simultaneously.
• Apply engine oil to the main axle and the drive
axle bearing.
New
891
234
567M
New
LS
M
New
21
2
ab
cc
1
2
EE

TRANSMISSION
6-80
6. Install:
• Shift fork 1 (L) “1”
• Shift fork 2 (C) “2”
• Shift fork 3 (R) “3”
• Shift cam “4”
(to the main axle and the drive axle)
TIP
• Apply engine oil to the shift fork grooves.
• Apply engine oil to the shift cam groove and
the bearing contact surface.
• Mesh the shift fork 1 (L) with the 5th wheel
gear “5” and “3” (R) with the 6th wheel gear “7”
on the drive axle.
• Mesh the shift fork 2 (C) with the 3rd/4th pin-
ion gear “6” on the main axle.7. Install:
• Long shift fork guide bar “1”
• Short shift fork guide bar “2”
• Spring “3”
TIP
• Screw the spring into the shift fork guide bar
lightly beforehand.
• Apply the engine oil on the shift fork guide
bars.
8. Check:
• Operation of shift cam and shift fork
• Transmission operation
Unsmooth operation  Repair.
3
12
6
2
4
5
3
7
1
E
E
E
2 13
E

RADIATOR
7-1
EAS2GB7328
TIP
This section is intended for those who have basic knowledge and skill concerning the servicing of
Yamaha motorcycles (e.g., Yamaha dealers, service engineers, etc.). Those who have little knowl-
edge and skill concerning servicing are requested not to undertake inspection, adjustment, disas-
sembly, or reassembly only by reference to this manual. It may lead to servicing trouble and
mechanical damage.
EAS2GB7329
RADIATOR
Removing the radiator
Order Part name Q’ty Remarks
CoolantDrain.
Refer to “CHANGING THE COOLANT” on
page 3-10.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case Refer to “THROTTLE BODY” on page 8-7.
1 Radiator guard 2
2 Radiator hose clamp 8 Loosen.
3 Radiator fan 1
12
13
New
New
New
LS
LS
3
458 Nm (0.8 m kgf, 5.8 ft Ibf)T.R.
6
7
89
10
112
2
2
2 22 2
1 1

WATER PUMP
7-4
EAS2GB7332
WATER PUMP
Removing the water pump
Order Part name Q’ty Remarks
CoolantDrain.
Refer to “CHANGING THE COOLANT” on
page 3-10.
Engine oilDrain.
Refer to “CHANGING THE ENGINE OIL” on
page 3-17.
Right crankcase cover Refer to “CLUTCH” on page 6-40.
1 Water pump housing 1
2 Dowel pin 2
3Gasket 1
4Washer 2
5Collar 1
6Gear 1
7Pin 1
8 Impeller shaft assembly 1
9 Oil seal 1
10 Bearing 1
11 Oil seal 1
9
8
2
2
3
1
10
6
7
5
4
4
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R.
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R.
New
New
New
E
11
New
E
LS
LS