Yamaha YZ 2023 Series, Owner'S Service Manual

Page: 269 / 378

RADIATOR
6-4
EAM30341
CHECKING THE RADIATOR
WARNING
EWA13030
A hot radiator is under pressure. Therefore,
do not remove the radiator cap when the en-
gine is hot. Scalding hot fluid and steam may
be blown out, which could cause serious in-
jury. When the engine has cooled, open the
radiator cap as follows:
Place a thick rag or a towel over the radiator
cap and slowly turn the radiator cap counter-
clockwise toward the detent to allow any re-
sidual pressure to escape. When the hissing
sound has stopped, press down on the radi-
ator cap and turn it counterclockwise to re-
move.
1. Check:
• Radiator fin “1”
Obstructions

Clean.
Apply compressed air to the rear of the radia-
tor.
Damage

Repair or replace.
TIP
Correct any flattened fins with a thin, flat-head
screwdriver.
2. Check:
• Radiator hose
•
Radiator pipe
Crack/damage

Replace.
3. Check:
• Radiator cap valve opening pressure
a. Install the radiator cap tester adapter “2”
and the radiator cap tester “3” to the radi-
ator cap “1”, and activate the tester to
check whether it can stay for 5 to 10 sec-
onds within standard pressure values.
TIP
Before attaching the cap to the tester, apply wa-
ter to its sealing surface.
No stay

Replace.
EAM30506
INSTALLING THE RADIATOR
1. Fill:
• Cooling system
(with the specified amount of the recom-
mended coolant)
Refer to “CHANGING THE COOLANT” on
page 3-21.
2. Check:
• Cooling system
Leaks

Repair or replace any faulty part.
3. Install:
•
Radiator cap tester “1”
•
Radiator cap tester adapter “2”
Radiator cap valve opening pres-
sure
107.9–137.3 kPa (1.08–1.37
kgf/cm², 15.6–19.9 psi)
Radiator cap tester
90890-01325
Mityvac cooling system tester kit
YU-24460-A
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984
Radiator cap tester
90890-01325
Mityvac cooling system tester kit
YU-24460-A
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984