Honda CB160 Shop Manual page 55

3. 13 CARBURETOR
3. Adjustment at low speed
The mixture covers the range from 1 /8 throttle to
idling. Adjustment is made by the air screw cutaway
and the throttle valve. (Refer to Fig. 3. 146)
a. Air screw
Adjustment of the mixture at idling is made by
the air screw. If the screw is turned clockwise,
the mixture becomes heavier ; if the screw is turned
counter-clockwise, the mixture becomes thinner.
However, the adjustment of the air screw should be
made with attention directed not only to idling but
also to starting and acceleration. Also observe
running performance in relation to density of the
mixture at the point where the throttly open.
b. Throttle valve cutaway
Near
1 /8
throttle, the density of the mixture
sometimes cannot be compensated by only the air
screw. In such case,
if
the mixture is too heavy,
a valve with a large cutaway number should be
employed (or vice versa). Thus adjustment of the
air screw is obtained.
• In CB 125 and 160, replacement of the screw
valve is not required since the cutaway is com-
pletely adjusted.
4. Adjustment of standard fuel level
As shown in Fig.
3.
145, the fuel level is esta-
blished at height (hi from the main bore bottom ; it
is different for every engine.
It is rather difficult to measure the actual fuel level.
Hence, this is determined by the float height. Ad-
justment of float. (Refer. to
Fig. 3.
147)
a. The carburetor should be turned upside down and
slid horizontally.
b. By pushing the float vertically and lightly with the
tip of a finger, find the pos,ition where the tip of
the float valve and the float arm contact slightly.
c.
The difference between the height of the tip of
the float and
that
of the carburetor body is equal
to h. If this height is not acceptable, adjustment
should be obtained by carefully bending the float
arm.
h
of Pw22 19.5 mm
1.78"1
Fig. 3. 146
Adjusting oir screw
Fig. 3. 147 Measuring standard fuel level
51