2015 YAMAHA YZ450F Owners Manual

KICKSTATER
5-46
EAS1SL5249
KICKSTATER
Removing the kick shaft
Order Part name Q’ty Remarks
Primary driven gear Refer to “CLUTCH” on page 5-37.
1 Kick idle gear 1
2 Kick shaft assembly 1
3 Spring guide 1
4 Torsion spring 1
5 Ratchet wheel 1
6 Kick gear 1
7 Kick shaft 1
For installation, reverse the removal proce-
dure.

KICKSTATER
5-47
EAS1SL5250REMOVING THE KICK SHAFT ASSEMBLY
1. Remove:
• Kick shaft assembly “1”
TIP
Unhook the torsion spring “2” from the hole “a”
in the crankcase.
EAS1SL5251CHECKING THE KICK SHAFT AND RATCH-
ET WHEEL
1. Check:
• Ratchet wheel “1” smooth movement
Unsmooth movement  Replace.
• Kick shaft “2”
Wear/damage  Replace the kick shaft as-
sembly.
• Spring “3”
Broken  Replace.
EAS1SL5252CHECKING THE KICK GEAR, KICK IDLE
GEAR AND RATCHET WHEEL
1. Check:
• Kick gear “1”
Wear/damage  Replace the kick shaft as-
sembly.
• Kick idle gear “2”
• Ratchet wheel “3”
• Gear teeth “a”
• Ratchet teeth “b”
Wear/damage  Replace.
EAS1SL5253INSTALLING THE KICK SHAFT ASSEMBLY
1. Install:
• Kick gear “1”
• Washer “2”
• Circlip “3”
• Ratchet wheel “4”
• Spring “5”
• Washer “6”
• Circlip “7”
(to the kick shaft “8”)
TIP
• Apply molybdenum disulfide oil to the inner
circumferences of the kick gear and ratchet
wheel.
• Align the punch mark “a” on the ratchet wheel
with the punch mark “b” on the kick shaft.
2. Install:
• Torsion spring “1”
(to the kick shaft “2”)
TIP
Make sure the stopper “a” of the torsion spring
fits into the hole “b” on the kick shaft.
31
2
a
b
3
12
New
New

KICKSTATER
5-48
3. Install:
• Spring guide “1”
TIP
Slide the spring guide into the kick shaft, make
sure the groove “a” in the spring guide fits on
the stopper of the torsion spring.
4. Install:
• Kick shaft assembly “1”
TIP
• Before installation, apply molybdenum disul-
fide grease to the contacting surfaces of the
kick shaft ratchet wheel guide “2” and the kick
shaft stopper “a”.
• Apply the engine oil on the kick shaft.
• Slide the kick shaft assembly into the crank-
case and make sure the kick shaft stopper “a”
fits into the kick shaft ratchet wheel guide.5. Install:
• Torsion spring “1”
TIP
Turn the torsion spring clockwise and hook into
the proper hole “a” in the crankcase.
EAS1SL5254INSTALLING THE KICK IDLE GEAR
1. Install:
• Kick idle gear “1”
• Washer “2”
• Circlip “3”
TIP
• Apply the engine oil on the kick idle gear inner
circumference.
• Install the kick idle gear with its depressed
side “a” toward you.
1 2a b
New

SHIFT SHAFT
5-49
EAS1SL5255
SHIFT SHAFT
Removing the shift shaft and stopper lever
Order Part name Q’ty Remarks
Primary driven gear Refer to “CLUTCH” on page 5-37.
1 Shift pedal 1
2 Shift shaft 1
3Oil seals 1
4Collars 1
5 Shift shaft spring 1
6Roller 1
7 Shift guide 1
8 Shift lever assembly 1
9 Shift lever 1
10 Pawl 2
11 Pawl pin 2
12 Spring 2
13 Stopper lever 1
LS
1 3
13
15 14
LT
610 11 12
118
1210
4
25
LT
7
LT
E
12 Nm (1.2 m kgf, 8.7 ft Ibf)T.R.
30 Nm (3.0 m kgf, 22 ftT.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
Ibf)
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

SHIFT SHAFT
5-50
Removing the shift shaft and stopper lever
Order Part name Q’ty Remarks
14 Stopper lever spring 1
15 Segment 1
For installation, reverse the removal proce-
dure.
LS
1 3
13
15 14
LT
610 11 12
118
1210
4
25
LT
7
LT
E
12 Nm (1.2 m kgf, 8.7 ft Ibf)T.R.
30 Nm (3.0 m kgf, 22 ftT.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
Ibf)
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

SHIFT SHAFT
5-51
EAS1SL5256REMOVING 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.
EAS1SL5257REMOVING 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.
EAS1SL5258
CHECKING THE SHIFT SHAFT
1. Check:
• Shift shaft “1”
Bends/damage/wear  Replace.
• Shift shaft spring “2”
Damage/wear  Replace.
EAS1SL5259CHECKING 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.
EAS1SL5260CHECKING 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
5-52
EAS1SL5261INSTALLING THE STOPPER LEVER
1. Install:
• Torsion spring “1”
• Collar “2”
• Stopper lever “3”
• Bolt (stopper lever) “4”
EAS1SL5262INSTALLING 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.
EAS1SL5263
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
5-53
4. Tighten:
• Shift guide bolt “1”
EAS1SL5264INSTALLING 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 and shift shaft.
2. Install:
• Oil seal
EAS1SL5265
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