Yamaha YZ450F 2021 - Checking the Cylinder Head Breather Hose; Checking the Exhaust System

ENGINE
3-18
3. Install:
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 4-1.
EAM30476
CHECKING THE CYLINDER HEAD
BREATHER HOSE
1. Check:
• Breather hose “1”
Crack/damage  Replace.
Loose connection  Connect properly.
NOTICE
ECA14920
Make sure the cylinder head breather hose is
routed correctly.
EAM30221
CHECKING THE EXHAUST SYSTEM
1. Remove:
• Exhaust pipe 1
• Exhaust pipe 2
Refer to “ENGINE REMOVAL” on page 5-6.
2. Remove:
• Exhaust pipe protector
3. Check:
• Exhaust pipe 1
• Exhaust pipe 2
4. Check:
• Silencer
Crack/damage  Replace.
5. Replace:
• Silencer fiber
a. Remove the bolts “1” and silencer body
“2”.
NOTICE
ECA25800
Do not hit the silencer stay “a” as it may do
damage to the silencer.
TIP
Remove the inner pipe while holding the silencer
in place with a vise etc.
b. Remove the rivets “3” and silencer cap “4”.
c. Remove the fiber inserts “5”.
1
1
a
1
2
4
3