How do you change fork oil in yz85?

To change the fork oil in a Yamaha YZ85, first, remove the front wheel and loosen the axle clamps. Then, using a fork seal driver, remove the fork caps and drain the old oil by inverting the forks. After draining, refill the forks with the appropriate type and amount of new oil, usually around 100-120ml per leg, and reassemble the forks, ensuring to properly torque the caps. Finally, reinstall the forks back onto the bike and check for any leaks.