The amount of backlash can be changed by turning the balancer shaft which has eccentric journals.
Start the engine and let it idle.
Loosen the clamp bolt [A] and turn the balancer shaft [B] clockwise [C] until the balancer gear makes a whining sound.
Turn the shaft counterclockwise [D] until the balancer gear whining sound disappears and tighten the clamp bolt.
Torque - Balancer Shaft Clamp Bolt: 9.8 N·m (1.0 kgf·m, 87 in·lb)

Balancer Installation
Balancer Damper InspectionBalance Adjustment
If the wheel always stops in one position, provisionally
attach a balance weight [A] on the rim at the marking using
adhesive tape.
Rotate the wheel 1/4 turn [B], and see whether or not the
wheel stops in this position. If it does, the correct balance
weight is being used.
If the whe ...
Subthrottle Sensor Output Voltage Inspection
Measure the output voltage at the subthrottle sensor in
the same way as input voltage inspection, note the following.
Disconnect the subthrottle sensor connector and connect
the setting adapter [A] between these connectors.
Special Tool - Throttle Sensor Setting Adapter: 57001
-1538
...
Transmission Assy Installation
Assemble the transmission assy (see Transmission Assy
Assembly).
Be sure that the dowel pins are in position.
Install the transmission assy on the crankcase.
Tighten:
Torque - Transmission Case Bolts: 20 N·m (2.0 kgf·m, 15
ft·lb)
Install:
Shift Shaft (see External Shift Mechani ...