Choke (Starting System); Adjusting The Fuel Level; Fuel Level Gauge Diagram - Honda C50 Shop Manual

46
Q) Throttle valve
@
Needle
I
@
Spring
3. ENGINE
@ Choke valve
@ Relief valve
1. CHOKE (START! G SYSTEM)
Since it is necessary to provide a rich mixture for
a short period during cold weather starting, choke
@
is incorporated. By raisi g the choke lever to the
full close position, the choke valve
@
can be com-
pletely closed. A r elief va lve
@
is installed on the
c:;hoke valve and kept in the closed position by the
spring
@ .
When the kick pedal is kicked with the
throttle valve
@
opened approximately
U: ,
the suction
pressure causes the fuel to b e discharged from the
pilot outlet
®
and the needl e jet
@,
and at the
same time, the suction pressu re ca uses the relief valve
to open a proper amount, permi tting the air to enter
and produces a fuel mixture which is idea l for starting.
@ Relief valve
After t he engine starts, the sucti o n pressure i n-
creases, opening the relief valve wider and furnishes
the co ld engine with the proper starting fuel mix ture.
In this way, the opening of the throttle valve causes
a co rr esponding opening of the relief valve and
permits t he worming up of the engine without manip-
ulating the choke lever. When the engine has warmed
up, merely positio n the choke valve to the fully open
position. (Fig.
3- 11 0)
Figure 3- 110. Choke
@ Float
arm
pin
Fig11re 3- 111. Fuel level adjustment
Figure 3- 112. Fuel level gaug e
5. ADJUSTING THE FUEL LEVEL
It is difficult to directly measur e the fuel level,
herefore, the fu el is det ermined by measuring the
height
(H )
of the float. (Fig.
3-111, 3- 112)
(1)
Position the carbu retor as shown in fig. 3 .111 '
w ith the float arm pin
@
to ward the top and
the float
@
at the botto m and tilt t he carburetor
to the point where the flo at arm
@
is about to
break co ntact w ith the flo at valve base. This
should · occur wh en t he carburetor is ti lt ed ap-
proximately 70 ° o r at any po int between 50 ° to
70°. That is, th e fl o at arm sho uld be at a po ini
where the base of th e valve is no t compressed.
121 In this position, the float bottom
@
is measured
fro m the carbureto r body
@
w ith the gaug e
®
to d etermin e the height
(HI.
Th e to lera nce of
the float positio n is 1 mm 10.040 in) bo th ways.
In o ther w ords, the gauge sho uld no t press the
float more than 1 mm, nor sho uld th ere be clear-
ance great er than 1 mm between the gaug e and
the flo at. Core should be excersized in making
the measurement since th e bose o f th e valve i s
spring loaded and can b e co mpressed into the
valve in which case, th e true closing p o int of th e
valve cannot be determin ed.