Yamaha YZF-R125 Service Manual: Balancer gear

Installing the shift shaft

1. Install: Stopper lever "1" Stopper lever spring "2" NOTE: Install the stopper lever spring as shown in the illustration. Hook the ends of the stopper lever spring onto the stoppe ...

Removing the primary drive gear and balancer gears

1. Loosen: Primary drive gear nut "1" NOTE: Place the aluminum plate "a" between the balancer drive gear "2" and the balancer driven gear "3", and then loosen the primary drive gear nut. ...

Other materials:

Checking the oil pump
1. Check: Oil pump drive gear Oil pump driven gear Oil pump housing Oil pump housing cover Cracks/damage/wear Replace the defective part(s). 2. Measure: Inner-rotor-to-outer-rotor-tip clearance "a" Outer-rotor-to-oil-pump-housing clearance "b" - Oil-pump-housing-to-inn ...

Checking the primary driven gear
1. Check: Primary driven gear "1" Damage/wear Replace the primary drive gear and clutch housing as a set. Excessive noise during operation  Replace the primary drive gear and clutch housing as a set. ...

Installing the shift forks and shift drum assembly
1. Install: Shift fork-L "1" Shift fork-C "2" Shift fork-R "3" Shift drum assembly "4" Springs Shift fork guide bar "5" NOTE: The embossed marks on the shift forks should face towards the right side of the engine and be in the following sequence: "R", "C", "L". 2. Check: Tr ...