Yamaha YZ 2020 Series Owner's Service Manual page 270

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 connections
Coolant leaks  Correct or replace.
• Radiator hoses
Bulges  Replace.
EWA19090
WARNING
When the radiator cap tester is removed,
coolant will spout; therefore, cover it with a
cloth beforehand.
6-5
RADIATOR