2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 222Get this manual
WATER PUMP
4.Measure: Impeller shaft tilt Out of specification Repeat steps (3) and (4)
CAUTION:
Make sure that the rubber damper and rubber damper holder are flush with the impellerMaximpeller shaft tilt: 0.15 mm (0.006 in)