r-CCK
Fuel
System
Satisfactory engine performance is largely depend-
ent upon correct fuel adjustments. However, adjust-
ments cannot fully compensate for low engine power
due to wear, etc. If trouble develops, follow an orderly
procedure to determine the cause before making any
adjustment.
Adjusting the carburetor is a means of obtaining the
correct fuel-to-air mixture for smooth, efficient oper-
ation. Always adjust in two steps, first the load
adjustment and then the idle adjustment.
Before adjusting the carburetor, be sure the ignition
system is working properly and the governor is
adjusted. Allow the engine to warm-up before start-
ing carburetor adjustments.
’
CARBURETOR ADJUSTMENTS
(Spec
A-G)
If carburetor
is
completely out of adjustment
so
the
engine will not run, open both needles 1 to 1-1/2 turns
off their seats to permit starting.
Do
not force needles
against their seats. This can bend the needle.
lnhalafion
of
exhausf gases mighf
n
result
in
serious personal injury
or
death. Be sure deadly exhaust gas
is
piped outside
and away,
from
windows, doors
or
ofher inlets
fo
building.
WARNING
1.
Apply a full load to engine.
2.
Turn in load needle (Figure 7) until engine speed
drops.
Then turn out needle until engine speed
returns to normal.
3.
Remove load from engine.
4. Turn idle needle
out
until engine speed drops
slightly.Then turn needle in until speed returnsto
normal.
Alternate Method (No-Load adjustment possible)
1.
Start engine and allow
it
to warm up.
2. Push in on governor mechanism to slow the unit
3.
Release governor mechanism to allow theengine
to accelerate. If engine accelerates evenly and
without a lag, the load needle setting is correct. If
not, adjust needle outward about
1/2
turn and
again slow down the engine and release the
mechanism. Continue until engine accelerates
evenly and without a time lag after releasing
governor.
,
down to about 400 to
500
rpm.
4.
Push in on governor mechanism to slow the unit
to400 to
500
rpm. Set idle needle for even opera-
tion
so
engine is firing on both cylinders and
running smoothly.
A
Zenith carburetor is used on Spec
B-G
engines.
Carburetor adjustments are the same as the Spec A
carburetor. The only difference is the location of
adjustment needles (Figure 7). The main-fuel ad-
justment needle
(A)
is on the bottom of carburetor.
FUEL IDLE
THROTTLE
/
ADJUSTMENT
STOPSCREW4
MAIN
FUEL
ADJUSTMENT
A
MAIN FUEL
ADJUSTMENT
SPEC
B-G
THIS DISTANCE
1/32
INCH
AT NO LOAD
THROVLE STOP
SCREW
r
SPEC
A
FIGURE
7.
ADJUSTING SIDEDRAFT CARBURETOR
15
Redistribution or publication of this document
by any means, is strictly prohibited.
Redistribution or publication of this document
by any means, is strictly prohibited.
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