YAMAHA YZ250F 2015 Owners Manual

SHIFT SHAFT
5-48
14 Stopper lever spring 1
15 Segment 1
For installation, reverse the removal proce-
dure.
Removing the shift shaft and stopper lever
Order Part name Q’ty Remarks
LS
1 3
10 Nm (1.0 m kgf, 7.2 ft lbf)
13
15 14
10 Nm (1.0 m kgf, 7.2 ft lbf)
30 Nm (3.0 m kgf, 22 ft lbf)
LT
610 11 12
118
1210
4
25
LT
7
LT
E
12 Nm (1.2 mkgf, 8.7 ftIbf)T.R.E

SHIFT SHAFT
5-49
EAS1SM5256REMOVING THE SHIFT GUIDE AND SHIFT
LEVER ASSEMBLY
1. Remove:
• Bolt (shift guide)
• Shift guide “1”
• Shift lever assembly “2”
TIP
Make sure that the shift lever assembly is re-
moved together with the shift guide.
EAS1SM5257REMOVING THE SEGMENT
1. Remove:
• Bolt (segment) “1”
• Segment “2”
TIP
Turn the segment counterclockwise until it
stops and loosen the bolt.
ECA1DX1021
NOTICE
If the segment gets an impact, the stopper
lever may be damaged. Take care not to
give an impact to it when removing the bolt.
EAS1SM5258
CHECKING THE SHIFT SHAFT
1. Check:
• Shift shaft “1”
Bends/damage/wear  Replace.
• Shift shaft spring “2”
Damage/wear  Replace.
EAS1SM5259CHECKING THE SHIFT GUIDE AND SHIFT
LEVER ASSEMBLY
1. Check:
• Shift guide “1”
• Shift lever “2”
•Pawl “3”
• Pawl pin “4”
• Spring “5”
Wear/damage  Replace.
EAS1SM5260CHECKING THE STOPPER LEVER
1. Check:
• Stopper lever “1”
Wear/damage  Replace.
• Torsion spring “2”
Broken  Replace.
1
2
1
2
3
4
5

SHIFT SHAFT
5-50
EAS1SM5261INSTALLING THE STOPPER LEVER
1. Install:
• Torsion spring “1”
• Collar “2”
• Stopper lever “3”
• Bolt (stopper lever) “4”
EAS1SM5262INSTALLING THE SEGMENT
1. Install:
• Segment “1”
• Segment bolt
TIP
• Align the notch “a” on the segment with the
pin “b” on the shift cam.
• With the stopper lever pushed down, install
the segment.
ECA1DX1022
NOTICE
If the segment gets an impact, the stopper
lever may be damaged. Take care not to
give an impact to it when tightening the bolt.
EAS1SM5263
INSTALLING THE SHIFT GUIDE AND SHIFT
LEVER ASSEMBLY
1. Install:
• Spring “1”
• Pawl pin “2”
•Pawl “3”
(to the shift lever “4”)
TIP
Apply the engine oil on the spring, pawl pin and
pawl.
2. Install:
• Shift lever assembly “1”
(to the shift guide “2”)
3. Install:
• Shift lever assembly “1”
• Shift guide “2”
TIP
• The shift lever assembly is installed at the
same time as the shift guide.
• Apply the engine oil on the segment bolt shaft. Bolt (stopper lever)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
LOCTITE®
Segment bolt
30 Nm (3.0 m·kgf, 22 ft·lbf)
T R..
42
13
LT
T R..
1
2
1 2

SHIFT SHAFT
5-51
4. Tighten:
• Shift guide bolt “1”
EAS1SM5264INSTALLING THE SHIFT SHAFT
1. Install:
• Roller “1”
• Shift shaft spring “2” (to shift shaft)
• Collar “3” (to shift shaft)
• Shift shaft “4”
TIP
Apply the engine oil on the roller, collar and
shift shaft.
2. Install:
• Oil seal
EAS1SM5265
INSTALLING THE SHIFT PEDAL
1. Install:
• Shift pedal “1”
• Shift pedal bolt “2”
TIP
Align the punch mark “a” on the shift shaft with
the punch mark “b” in the shift pedal. Shift guide bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
LOCTITE®
T R..
1 1
LT
E
E
1
23
4
New
Shift pedal bolt
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
T R..
a
12b

OIL PUMP AND BALANCER GEAR
5-52
EAS1SM5266
OIL PUMP AND BALANCER GEAR
Removing the oil pump
Order Part name Q’ty Remarks
Primary driven gear Refer to “CLUTCH” on page 5-35.
Right crankcase cover Refer to “CLUTCH” on page 5-35.
1 Oil pump assembly 1
2 Oil pump cover 1
3 Outer rotor 1
4 Dowel pin 1
5 Inner rotor 1
6 Oil pump drive shaft 1
7 Rotor housing 1
For installation, reverse the removal proce-
dure.
2.0 Nm (0.20 mkgf, 1.4 ftIbf)T.R
.
5 Nm (0.5 mkgf, 3.6 ftIbf)T.R
.
LT
E
3
2
1
4
5
7
6

OIL PUMP AND BALANCER GEAR
5-53
Removing the balancer
Order Part name Q’ty Remarks
Primary driven gear Refer to “CLUTCH” on page 5-35.
Right crankcase cover Refer to “CLUTCH” on page 5-35.
Stator Refer to “AC MAGNETO” on page 5-58.
1 Nut (balancer) 1
2 Nut (primary drive gear) 1
3 Nut (balancer shaft driven gear) 1
4 Conical washer 1
5Balancer 1
6 Conical washer 1
7 Primary drive gear 1
8Collar 1
9 Balancer shaft drive gear 1
10 Conical washer 1
11 Balancer weight gear 1
12 Collar 1
For installation, reverse the removal proce-
dure.
T
.R.
75 Nm (7.5 mkgf, 54 ftlbf)T.R.
50 Nm (5.0 mkgf, 36 ftIbf)T
.R.
New
6
12
11
7
8

OIL PUMP AND BALANCER GEAR
5-54
EAS1SM5267REMOVING THE BALANCER
1. Loosen:
• Balancer nut “1”
• Primary drive gear nut “2”
• Balancer weight gear nut “3”
TIP
Place an aluminum plate “a” between the teeth
of the balancer drive gear “4” and balancer
weight gear “5”.
EAS1SM5268CHECKING THE PRIMARY DRIVE GEAR,
BALANCER SHAFT DRIVE GEAR, AND
BALANCER WEIGHT GEAR
1. Check:
• Primary drive gear “1”
• Balancer shaft drive gear “2”
• Balancer weight gear “3”
Wear/damage  Replace.
EAS1SM5269CHECKING THE BALANCER
1. Check:
•Balancer
Crack/damage  Replace.
EAS1SM5270CHECKING THE OIL PUMP
1. Check:
• Oil pump drive gear
• Oil pump driven gear
• Oil pump housing
• Oil pump housing cover
Cracks/damage/wear  Replace the defec-
tive part(s).
2. Measure:
• Inner-rotor-to-outer-rotor-tip clearance “a”
• Outer-rotor-to-oil-pump-housing clearance
“b”
• Oil-pump-housing-to-inner-rotor-and-outer-
rotor clearance “c”
Out of specification  Replace the oil pump.
1
4
a5
2
4a
5
3
Inner-rotor-to-outer-rotor-tip
clearance
Less than
0.150 mm (0.0059 in)
Outer-rotor-to-oil-pump-housing
clearance
0.13–0.18 mm (0.0051–0.0071 in)
Oil-pump-housing-to-inner-and-
outer-rotor
clearance
0.06–0.11 mm (0.0024–0.0043 in)

OIL PUMP AND BALANCER GEAR
5-55
3. Check:
• Oil pump operation
Rough movement  Repeat steps (1) and
(2) or replace the defective part(s).
EAS1SM5271ASSEMBLING THE OIL PUMP
1. Install:
• Oil pump drive shaft “1”
• Inner rotor “2”
• Dowel pin “3”
TIP
• Apply the engine oil on the oil pump drive
shaft and inner rotor.
• Fit the dowel pin into the groove in the inner
rotor.2. Install:
• Outer rotor “1”
TIP
Apply the engine oil on the outer rotor.
3. Install:
• Oil pump cover “1”
• Oil pump cover screw “2”
EAS1SM5272INSTALLING THE OIL PUMP AND BALANC-
ER GEAR
1. Install:
• Oil pump assembly “1”
• Oil pump assembly bolt “2”
ECA1DX1023
1. Inner rotor
2. Outer rotor
3. Oil pump housing
b
a 1
2
3
c
21
3
Oil pump cover screw
2.0 Nm (0.20 m·kgf, 1.4 ft·lbf)
Oil pump assembly bolt
5 Nm (0.5 m·kgf, 3.6 ft·lbf)
LOCTITE®
1
E
T R..
2
1
T R..
1
2
LT

OIL PUMP AND BALANCER GEAR
5-56
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
5-57
c
d
6 6
78
8 b