NOTICE
Never drop the air switching valve especially on a hard surface. Such a shock to the air switching valve can damaged it.

Air Suction Valve Inspection
Air Switching Valve InstallationSprocket Wear Inspection
Visually inspect the engine and rear sprocket teeth for
wear and damage.
If the teeth are worn as illustrated, replace the sprocket,
and inspect the drive chain wear (see Drive Chain Wear
Inspection in the Periodic Maintenance chapter).
Worn Tooth (Engine Sprocket) [A]
Worn Tooth (Rear ...
Spring Preload Adjustment
Remove the rear shock absorber from the frame (see
Rear Shock Absorber Removal).
Loosen the locknut and turn out the adjusting nut to free
the spring.
Special Tools - Hook Wrench T=3.2 R37: 57001-1539
Hook Wrench R=35: 57001-1580
To adjust the spring preload, turn in the adjusting n ...
Camshaft Installation
NOTE
The exhaust camshaft has a 1001 EX mark [A] and the
intake camshaft has a 3154 IN mark [B]. Be careful not
to mix up these shafts.
Install the camshaft sprockets as shown in the figure.
#4 Cam Positions [A]
Intake Camshaft Sprocket [B]
Exhaust Camshaft Sprocket [C]
The int ...