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 cylinder and piston
1. Check: Piston wall Cylinder wall Vertical scratches Replace the cylinder, and replace the piston and piston rings as a set. 2. Measure: Piston-to-cylinder clearance a. Measure cylinder bore "C" with the cylinder bore gauge. NOTE: Measure cylinder bore "C" by takin ...

Installing the crankshaft
1. Install: Crankshaft "1" NOTE: Install the crankshaft with the crankshaft installer pot "2", crankshaft installer bolt "3", adapter (M12) "4" and spacer (crankshaft installer) "5". CAUTION:To avoid scratching the crankshaft and to ease the installation procedure, lubricate ...

Checking the valves and valve guides
The following procedure applies to all of the valves and valve guides. 1. Measure: Valve-stem-to-valve-guide clearance Out of specification Replace the valve guide. Valve-stem-to-valve-guide clearance = Valve guide inside diameter "a" - Valve stem diameter "b" 2. Replace: ...