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 InspectionSpecifications
Connecting Rod Big End Bearing Insert Selection
Crankshaft Main Bearing Insert Selection
*: The bearing inserts for Nos. 2 and 4 journals have an oil groove,
respectively. ...
Stem, Stem Bearing Installation
Replace the bearing outer races with new ones.
Drive them into the head pipe at the same time.
Special Tools - Head Pipe Outer Race Press Shaft [A]:
57001-1075
Head Pipe Outer Race Driver,
55 [B]: 57001
-1446 or Bearing Driver Set: 57001-1129
Apply grease to the outer races.
...
Water Temperature Sensor Resistance Inspection
Refer to the Water Temperature Sensor Inspection in the
Electrical System chapter.
If the reading is within the standard, but the problem still
exists, replace the ECU (see ECU Removal/Installation in
the Fuel System (DFI) chapter).
Water Temperature Sensor Circuit
1. ECU
2. Water T ...