1. When overhauling the engine, replace all gaskets, seals and O-rings. All gasket surfaces, oil seal lips and O-rings must be cleaned.
2. During reassembly, properly oil all mating parts and bearings and lubricate the oil seal lips with grease.

Replacement parts
Lock washers/plates and cotter pinsAssembling the front brake caliper
WARNING
Before installation, all internal brake components
should be cleaned and lubricated
with clean or new brake fluid.
Never use solvents on internal brake components
as they will cause the brake caliper
dust seals and piston seals to swell and
distort.
...
Checking the primary drive gear
1. Remove:
Primary drive gear
Refer to "BALANCER GEAR" on page 5-53.
2. Check:
Primary drive gear
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
...
Adjusting the throttle cable free play
Throttle cable free play
The throttle cable free play should measure
3.0-5.0 mm (0.12-0.20 in) at the
throttle grip. Periodically check the
throttle cable free play and, if necessary,
adjust it as follows.
TIP
The engine idling speed must be correctly
adjusted before checkin ...