If the surface is corroded or if the blades are damaged, replace the impeller

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyMoving Off
Check that the side stand is up.
Pull in the clutch lever.
Shift into 1st gear.
Open the throttle a little, and start to
let out the clutch lever very slowly.
As the clutch starts to engage, open
the throttle a littlemore, giving the engine
just enough fuel to keep it from
stallin ...
Valve Guide Installation
Apply engine oil to the valve guide outer surface before
installation.
Heat the area around the valve guide hole to about 120
150°C (248 302°F).
NOTICE
Do not heat the cylinder head with a torch. This will
warp the cylinder head. Soak the cylinder head and
heat the oil.
Usin ...
Master Cylinder Rubber Parts Replacement
Front Master Cylinder Disassembly
Remove the front master cylinder (see Front Master Cylinder
Removal in the Brakes chapter).
Remove the seal cover [A], circlip [B], connector [C] and
O-ring [D].
Special Tool - Inside Circlip Pliers: 57001-143
Unscrew the locknut [E] and pivot bolt ...