Yamaha YZ450FN 2022 Owner's Service Manual page 266

4. Activate the tester to apply the test pressure.
Test pressure value
137.3 kPa (1.37 kgf/cm², 19.9 psi)
ECA24270
NOTICE
• Do not apply such a high pressure as ex-
ceeds the test pressure.
• Make sure that a checkup after the cylinder
head gasket is replaced is made after 3 min-
utes of warm-up.
• Make sure that coolant is filled up to the up-
per level beforehand.
5. Check:
• Pressure value
No stay for 5 to 10 seconds at the test pres-
sure value  Correct.
• Radiator
• Radiator hose connection
Coolant leaks  Correct or replace.
• Radiator hose
Bulges  Replace.
EWA19090
WARNING
When the radiator cap tester is removed,
coolant will spout; therefore, cover it with a
cloth beforehand.
6-5
RADIATOR