2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 190Get this manual
CRANKSHAFT AND OIL PUMP
3.Check: Oil pump operation Unsmooth Repeat steps #1 and #2 or replace the defective parts
CRANKSHAFT INSPECTION 1.Measure: Crank width Out of specification Replace the crankshaftCrank width: 62.9563.00 mm (2.4782.480 in)
Side clearance Out of specification Replace the crankshaftBig end side clearance: 0.250.75 mm (0.0100.030 in) Limit: 1.0 mm (0.040 in)