Yamaha YZ250 2021 Owner's Manual

CHASSIS3-17Adjusting the drive chain slackWARNINGEWA13120Securely support the vehicle so that there isno danger of it falling over.1. Adjust:• Drive chain slacka. Loosen the wheel axle nut “1”.b. Loosen both locknuts “2”.c. Turn the adjusting bolt “3” until the speci-fied drive chain slack is obtained.TIP• To maintain the proper wheel alignment, adjustboth sides evenly.• Push the rear wheel forward to make sure thatthere is no clearance between the swingarmend plates and the ends of the swingarm.d. Tighten the wheel axle nut.e. Tighten the drive chain puller locknut.EAM30251LUBRICATING THE DRIVE CHAINThe drive chain consists of many interactingparts. If the drive chain is not maintained proper-ly, it will wear out quickly. Therefore, the drivechain should be serviced, especially when thevehicle is used in dusty areas.This vehicle has a drive chain with small rubberO-rings between each side plate. Steam clean-ing, high-pressure washing, certain solvents,and the use of a coarse brush can damagethese O-rings. Therefore, use only kerosene toclean the drive chain. Wipe the drive chain dryand thoroughly lubricate it with engine oil orchain lubricant that is suitable for O-ring chains.Do not use any other lubricants on the drivechain since they may contain solvents that coulddamage the O-rings.EAM30247CHECKING AND ADJUSTING THESTEERING HEAD1. Use a maintenance stand to raise the frontwheel off the ground.WARNINGEWA13120Securely support the vehicle so that there isno danger of it falling over.2. Check:• Steering headGrasp the bottom of the front fork legs andgently rock the front fork.Blinding/looseness  Adjust the steeringhead.3. Remove:• Handlebar• Upper bracket4. Adjust:• Steering heada. Remove the washer “1”.b. After loosening the ring nut “2” with asteering nut wrench “3”, tighten it to thespecified torque.TIP• Set the torque wrench at a right angle to thesteering nut wrench.• Move the steering to the left and right a coupleof times to check that it moves smoothly.Drive chain slack (Maintenancestand)48.0–58.0 mm (1.89–2.28 in)Rear wheel axle nut125 N·m (12.5 kgf·m, 92 lb·ft)Drive chain puller locknut19 N·m (1.9 kgf·m, 14 lb·ft)21 3T R..T R..Recommended lubricantChain lubricant suitable for O-ring chains1