Engine - Yamaha YZ450FY 2009 Owner's Service Manual

ENGINE

CHECKING THE COOLANT LEVEL
Do not remove the radiator cap "1", drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury. When the en-
gine has cooled, place a thick towel over the
radiator cap, slowly rotate the cap counter-
clockwise to the detent. This procedure al-
lows any residual pressure to escape. When
the hissing sound has stopped, press down
on the cap while turning counterclockwise
and remove it.
Hard water or salt water is harmful to the en-
gine parts. You may use distilled water, if
you can't get soft water.
1. Place the machine on a level place, and hold
it in an upright position.
2. Remove:
• Radiator cap
3. Check:
• Coolant level "a"
Coolant level low → Add coolant.
1. Radiator
CHANGING THE COOLANT
Do not remove the radiator cap when the en-
gine is hot.
Take care so that coolant does not splash
on painted surfaces. If it splashes, wash it
away with water.
1. Place a container under the engine.
2. Remove:
• Engine guard "1"
• Coolant drain bolt "2"
3. Remove:
• Radiator cap
Drain the coolant completely.
4. Clean:
• Cooling system
Thoroughly flush the cooling system with
clean tap water.
5. Install:
• Copper washer
• Coolant drain bolt
Coolant drain bolt:
10 Nm (1.0 m•kg, 7.2 ft•lb)
• Engine guard
• Bolt (engine guard)
Bolt (engine guard):
10 Nm (1.0 m•kg, 7.2 ft•lb)
6. Fill:
• Radiator
• Engine
To specified level.
3-6
ENGINE