Yamaha YZ250FM 2021 Owner's Service Manual

CLUTCH5-51EAM30108REMOVING THE CLUTCH1. Straighten the clutch boss nut rib “a”.2. Remove:• Clutch boss nut “1”• Conical washer “2”• Clutch boss “3”TIP• While holding the clutch boss with the univer-sal clutch holder “4”, loosen the clutch bossnut.• Do not use an impact wrench for removing theclutch boss nut.EAM30109CHECKING THE FRICTION PLATES1. Check:• Friction plateDamage/wear  Replace the friction platesas a set.2. Measure:• Friction plate thicknessOut of specification  Replace the frictionplates as a set.TIPMeasure it at four points on the friction plate.EAM30110CHECKING THE CLUTCH PLATES1. Check:• Clutch plateDamage  Replace the clutch plates as aset.2. Measure:• Clutch plate warpage(with a surface plate and thickness gauge)Out of specification  Replace the clutchplates as a set.EAM30111CHECKING THE CLUTCH SPRINGS1. Check:• Clutch springDamage  Replace the clutch springs as aset.2. Measure:• Clutch spring free lengthOut of specification  Replace the clutchsprings as a set.EAM30112CHECKING THE CLUTCH HOUSING1. Check:• Clutch housing dogs “1”Damage/pitting/wear  Deburr the clutchhousing dogs or replace the clutch housing.TIPPitting on the clutch housing dogs will cause er-ratic clutch operation.Universal clutch holder90890-04086Universal clutch holderYM-91042a223411234Friction plate thickness2.70–2.90 mm (0.106–0.114 in)Wear limit2.60 mm (0.102 in)Thickness gauge90890-03268Feeler gauge setYU-26900-9Clutch plate thickness1.50–1.70 mm (0.059–0.067 in)Warpage limit0.10 mm (0.004 in)Clutch spring free length46.20 mm (1.82 in)Clutch spring free length limit43.89 mm (1.73 in)