Service Manual

2-8 PERIODIC MAINTENANCE
Periodic Maintenance Procedures
Valve Clearance Inspection
NOTE

Valve clearance must be checked when the engine is cold (at room
temperature).
•
Remove the rocker cover (see Engine Top End chapter).
•
Place the piston at top dead center (TDC) of the compression stroke
turning the crankshaft clockwise facing the flywheel.
No.1 Cylinder:

The left projection [A] on the flywheel is faced with the right leg [B]
on the #1 ignition coil [C] as shown.

Check the intake and exhaust valves are closed completely, if not, turn
the flywheel one turn (360

) clockwise and face the left projection with
the right leg again.
No.2 Cylinder:

The left projection [A] on the flywheel is faced with the right leg [B]
on the #2 ignition coil [C] as shown. Follow No.1 Cylinder alignment.
•
Then check the valve clearance.

Using a thickness gauge [A], measure the valve clearance beween
the rocker arm [B] and the valve stem end.
If the valve clearance is incorrect, adjust it.
Valve Clearance (when cold)
Intake, Exhaust 0.10 ~ 0.15 mm (0.004 ~ 0.006in.)
Valve Clearance Adjustment
•
Since valve repairs change the valve clearance, adjust the valve
clearance to the specification.
•
Assemble the cylinder head and install the cylinder head assembly
on the block (see Engine Top End chapter).
•
Turn the crankshaft to the proper direction until the piston is at TDC
of the compression stroke (described above).
•
Loosen the lock screws [A] and valve clearance adjusting nuts [B].
•
Insert a 0.10 mm (0.004 in.) thickness gauge [C] between the rocker
arm and valve stem, and tighten the adjusting nut until the thickness
gauge begins to bind between the rocker arm and valve stem end.
Use a sweeping motion with the thickness gauge while making this
adjustment.
Valve Clearance (when cold)
Intake, Exhaust 0.10 ~ 0.15 mm (0.004 ~ 0.006in.)
•
Holding the adjusting nut with a wrench, tighten the lock screw to the
specified torque.
Torque - Valve Clearance Lock Screws: 6.9 N 1 m (0.70 kgf 1 m, 61 in 1 lb)
•
Do not overtighten.
•
Remeasure any clearance that was adjusted. Readjust if necessary.