Yamaha YZ 2017 Series, Owner'S Service Manual, Page: 96 / 410

ENGINE
3-8
EASB29B070
ENGINE
EASB29B071
CHECKING THE COOLANT LEVEL
EWA
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Stand the vehicle upright on a level surface.
2. Remove:
• Radiator cap “1”
3. Check:
• Coolant level
Maximum level “a” or below

Add coolant
up to the maximum level.
ECA
NOTICE
• Adding water instead of coolant lowers the
antifreeze content. If, therefore, water is
used instead of coolant, check, and if nec-
essary, adjust the antifreeze concentra-
tion.
• Use only distilled water. However, if dis-
tilled water is not available, soft water may
be used.
4. Start the engine, warm this up for 3 minutes,
and then stop it.
5. Check:
• Coolant level
TIP
Before checking the coolant level, wait a few
minutes until the coolant has settled.
EASB29B072
CHECKING THE COOLING SYSTEM
1. Remove:
• Seat
• Side cover (left/right)
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-7.
2. Check:
• Radiator
• Radiator hoses
Crack/damage

Replace.
Refer to “RADIATOR” on page 6-1.
3. Install:
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-7.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
EASB29B073
CHANGING THE COOLANT
EWA
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Place a container under the engine.
2. Remove:
• Coolant drain bolt “1”
3. Remove:
• Radiator cap
Slowly loosen the radiator cap to drain cool-
ant.
TIP
When the radiator cap is loosened, coolant will
gush out transversely; therefore, bring the con-
tainer near to the outlet.
4. Thoroughly flush the cooling system with
clean tap water.
1. Radiator
1