Honda Z50A Shop Manual page 28

26
(21 Ne>.t turn the air screw slowly back and forth to obtain the point of the
highest mm
(3) Ir the engine rpm has increased as resu lt of sec11on (21 above. reset the
engine speed back to lhe proper rpm with the throttle stop screw.
(4) Once again manuplate the air screw to see
if
the rpm
will
be increased
(5) If the speed should increase again. perform secuon (3) (4) above again
Howavor the ad1ustment of the air screw should be within 1
% +
.!,i
of a turn.
b Ad1us t 111g the slow speed
The
(uel 11w:tu1
e
ad1ustment between idle
10
~
thro11le opening 1s made by the
air screw and the
cut
away on the throttle valve
(1) Atr sc rew
Turning 1n 1he clockwise d1rec11on will produce a nch mixture.
(21 Tt,rollle valve cut away
In lhe ,11cinuy
1 ,,
throttle opening there may be cases where the fuel m1x1ure
cannot be adn,sted by the air screw only In such case 1f the fuel mixture
1s
too rich. the throttle valve must be replaced wnh one having
a
cutaway ol
a large number sn:e dnd then read1us1 the air screw .
c Ad1us1mg intermad1ate sp13ed
At the throttle opening range between
"s - ~1
the fuel mixture adjustment 1s made
primary by the oos1t1on of the set needle steps and replacement of the cut awav
of 1he throttle valve However changing the cutaway of the thronle valve will also
affect the tl11 uttlo upe111ng between the
11
to
1
11 ;.
therefore . the ad1ustment of the
1n1arrnad1a1e speed
t,y
reµlac1ng the th 1 onle valve cut away only is very d1ff1cult.
It
1s
recommended
rhat the ad1us1mem for the
111termed1ete
speed be made by
the
Jet needle.
and
s1ay
w11hin the range of acceptable acceleration performance srnce
this would pmv1df' greater fuel economy
d AIJJUSIHlQ Ille
high
5peed
Whtie dt1ving at 111911 speed, II the speed increases wnen 1he choke 1s closed sllgnily.
11 is an 1nd1cc:111011 that 11,e carburetor 1s set too IP.an Progressively replace the
main 1et w1tf 1 one of a- large size and reacJJust 1he carburetor
Note Mair, Jet s,zes are numbered m the
f
oilow1ng manner
Above ;; 100 105. 110. 115
Belc.>w :; 100 98. 95. 92. 90
If the speed drops when the choke 1s closed slightly. it indicates that the main
)el
is uither of the proper size or tha1
it
is
too large.
in
which
case. perform the
following check to make the determination
.. Proper 101
s1Le
Progress,velv rtJptace the main Jet w1tt, one of a smaller size unul 1here is a drop
in speed and the speed increases when the ct,oke is closed sllg'tllly the installed
it!t 1s too small and should be replaced with one of a size larger this ts the proper
Jet size.
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