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 pinsRemoving the valves
The following procedure applies to all of the
valves and related components.
NOTE:
Before removing the internal parts of the cylinder
head (e.g., valves, valve springs, valve seats),
make sure the valves properly seal.
1. Check:
Valve sealing
Leakage at the valve seat Check
the valve
...
Disassembling the front wheel
1. Remove:
Oil seal
Wheel bearings
a. Clean the surface of the front wheel hub.
b. Remove the oil seal "1" with a flat-head
screwdriver.
NOTE:
To prevent damaging the wheel, place a rag "2"
between the screwdriver and the wheel surface.
c. Remove the wheel bearings "3" with a ge ...
Checking the front brake caliper
1. Check:
Brake caliper pistons "1"
Rust/scratches/wear Replace the
brake
caliper assembly.
Brake caliper body "2"
Cracks/damage Replace the brake
caliper
assembly.
Brake fluid delivery passages
(brake caliper body)
Obstruction Blow out with
compressed air.
...