HYOSUNG COMET 125 Service Manual page 20

If the clearance is out of specification, first remove the
cam chain tensioner, camshaft housing, camshaft.
To install the tappet shim at original position, record
the shim NO. and clearance with A , B , C , D
mark on the cylinder head as the illustration.
Select the tappet that agree with tappet clearance
(vertical line) and shim NO.(horizontal line) as refer to the
tappet shim selection chart. (Refer to page 7-33 34)
Adjust valve timing, install the camshaft housing and the
tensioner.
After the crankshaft rotate about 10 times, measure the
valve clearance.
If the clearance be not agree, adjust the standard clea-
rance as the same manner above.
In case that valve adjustment which there is no the
tappet shim selection chart, please follow instructions
of example in the below.
For example, the intake clearance is 0.4 and the shim
is 170 (1.70 mm), select 195 (1.95 mm) of the shim
which 170 (1.70 mm) of the shim add up the excess
clearance 0.25 mm when adjust with the standard
0.15 as the intake standard clearance 0.1 0.2 mm.
CAUTION
Valve clearance should be checked when the
engine is cold.
If you rotate the crankshaft about 10
don t
times before measuring the valve clearance,
there is no meaning of valve clearance.
Rotate the magneto rotor to set the rear cylinder s
piston at TDC(Top Dead Center) of the compression
stroke.
(Rotate the rotor 285 counter-clockwise from the
F line, and until the
aligned with the center of hole on the crankcase.)
Inspect the rear cylinder s valve clearance with the
same manner of the front cylinder.
R line on the rotor is
PERIODIC MAINTENANCE 2-4