Yamaha YZ250FM 2021 Owner's Service Manual

CHASSIS3-26h. Repeat steps (d) to (g) until all of the airbubbles have disappeared from the brakefluid in the plastic hose.TIPDuring the procedure, keep adding brake fluid tothe reservoir.NOTICEECA24320• Wipe off any brake fluid on the brake discs,tires, wheels, etc.• Brake fluid may erode painted surfaces orplastic parts. Always clean up spilled fluidimmediately.i. Tighten the bleed screw.j. Pour brake fluid to the reservoir up to thespecified level.Refer to “CHECKING THE BRAKE FLUIDLEVEL” on page 3-24.WARNINGEWA13110After bleeding the hydraulic brake system,check the brake operation.EAM30481DRIVE CHAIN SLACKNOTICEECA13550A drive chain that is too tight will overloadthe engine and other vital parts, and one thatis too loose can skip and damage the swing-arm or cause an accident. Therefore, keepthe drive chain slack within the specified lim-its.Checking the drive chain slack1. Use a maintenance stand to raise the rearwheel off the ground.WARNINGEWA13120Securely support the vehicle so that there isno danger of it falling over.2. Shift the transmission into the neutral posi-tion.3. Pull the drive chain up above the drive chainguide installation bolt with a force of about 50N (5.0 kgf, 37 lbf).4. Check:• Drive chain slack “a”Out of specification  Regulate.TIPMeasure drive chain slack between the drivechain guide and the bottom of the chain asshown.Adjusting 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.Bleed screw6 N·m (0.6 kgf·m, 4.4 lb·ft)T R..Drive chain slack (Maintenancestand)50.0–60.0 mm (1.97–2.36 in)Wheel axle nut135 N·m (13.5 kgf·m, 100 lb·ft)aa13 2T R..