To replace the timing belt on a Yamaha bike, remove the camshafts, starter motor, throw-out gear, flywheel cover and nut, and flywheel in this order. Also remove the motor gear on the crankshaft to uncover the timing belt and detach the timing belt guide. Change the belt, and reconstruct the engine starting with the parts removed last.
Unlock the seat and the tank during the process of removing the camshaft, then adjust the valves. The timing belt sits behind the flywheel, which is accessible once the cover, stator and gasket are off.
Use a screwdriver on the bolts, and pay attention to where the bolts go since they vary in size. Clean the parts during the procedure to prevent dirt from entering the engine. Use oils, degreaser spray and a brush for cleaning.
Use an electric rattle gun on the flywheel nut to unfasten it, although a wrench also works. If using a wrench, take care not to stress the engine and bend the parts. Use a flywheel puller to disengage the flywheel from the crankshaft. Remove the bolts holding the timing belt guide.
Once the old chain is out, poke the new one into the engine case. This procedure requires tools that include wrenches, T-bars, a socket set, Allen wrenches and tie-wire, in addition to pliers, a magnet, Vernier calipers, circlip pliers and an impact gun. A torque wrench and a flywheel puller are also required. Replacing the timing belt takes about an hour and a half.