Honda CB300R 2019 Owner's Manual page 91

Remove the reserve tank cap/dipstick and
1.
add fluid while monitoring the coolant
level.
Do not overfill above the upper level
u
mark.
Make sure no foreign objects enter the
u
reserve tank opening.
Securely reinstall the reserve tank cap/
2.
dipstick.
WARNING
3
Removing the radiator cap while the
engine is hot can cause the coolant to
spray out, potentially scalding you.
Always let the engine and radiator cool
down before removing the radiator cap.
Coolant
Reserve tank cap/dipstick
Changing Coolant
Have your dealer change the coolant unless
you have the proper tools and are
mechanically qualified.
Changing Coolant
u
89