1981-1984 Official Honda ATC250R Shop Manual, Page 154Get this manual
REAR WHEELBRAKEDRIVE MECHANISM
ATe 2S0R
Remove the four riven flange nutsRemove the sprocket from the flange
INSPECTION
Check the damper rubbers for damageCheck the condition of the final driven sprocket teethReplace the sprocket if it is worn or damaged or the damper rubbers are damagedNOTE If the riven sprocket is worn or damaged, the drive chain and the drive sprocket must be inspectedNever install new drive chain on worn sprocket or worn chain on new sprocketsBoth chain and sprockets must be in good condition or the replacement chain or spro ckets will wear rapidly_