2002 Yamaha YFM660 Grizzly factory service and repair manual, Page 243Get this manual
RADIATOR
CHECKING THE RADIATOR 1.Check: Radiator fins Obstruction CleanApply compressed air to the rear of the radiatorDamage Repair or replaceNOTE: Straighten any flattened fins with thin, flathead screwdriver2.Check: Radiator hoses Cracksdamage Replace
3.Measure: Radiator cap opening pressure Below the specified pressure Replace the radiator capRadiator cap opening pressure: 93.3122.7 kPa (0.9331.227 kgcm2, 13.5317.79 psi) Measurement steps: Install the radiator cap tester and adapter onto the radiator cap 3Radiator cap tester: PNYU-24460-01, 90890-01325 Adapter: PNYU-33984, 90890-01352