To Adjust Carburetor - Craftsman 28903 Owner's Manual

2. Checkthat holes'A" in governorcontrol
lever and hole
in governor plate line-
up. If holes '_' are not aligned, loosen
clamp screw and move throttle cable until
holes are aligned. Tighten clamp screw
securely°
Governor Control Lever Governor
Control Ptate
' i
_--_. _,:_ c,
Holes 'At'-'P'_'_/_J_llb,_l _ Throttle
[ _;I Clamp _b_jl_,_j Cable
"-- '_/J Screw
TO ADJUST CARBURETOR
NOTE: The carburetor on this engine is
low emission. It is equipped with an idle
fuel adjusting needle with a limiter cap,
which allows some adjustment within the
limits allowed by the cap. Do not attempt
to remove the limiter cap. Tile limiter cap
cannot be removed without breaking the
adjusting needle,
The carburetor has been preset at the fac-
tory and adjustment should not be neces-
saryo However, minor adjustment may be
required to compensate for differences in
fuel, temperature, altitude or load. If the
carburetor does need adjustment, proceed
as follows:
In general, turning idle mixture valve in
(clockwise) decreases the supply of fuel to
the engine giving a leaner fuel/air mixture°
Turning the idle mixture valve out (counter-
clockwise) increases the supply offuel to the
engine giving a richer fuel/air mixture,
IMPORTANT: Damage to the needle valve
and the seat in carburetor may result if screw
is turned in too tight.
PRELIMINARY SETTING
'I. Aircleanerassembty must be assembled
to the carburetorwhen making carburetor
adjustments°
2. Be sure the throttle control cable is ad-
justed properly (see above).
FINAL SETTING -
1. Start engine and allow to warm for five
minutes. Make final adjustments with
engine running and shift/motion control
lever in neutral (N) position°
2. Move throttle control lever to slow posi-
tiono With finger, rotate and hold throttle
lever against idle speed screw. Turn idle
speed screw to attain 1750 RPMo
3. While still holding throttle lever against
idle speed screw, turn idle mixture
valve full travel clockwise then counter-
clockwise until engine runs rough, TiJrn
valve to a point midway between those
two positions, Release throttle lever,
ACCELERATION TEST -
4, Move throttle control lever from slow
to fast position, If engine hesitates or
dies, turn idle mixture valve out (coun-
terclockwise) 1/8 turn. Repeat test and
continue to adjust, if necessary, until
engine accelerates smoothly.
High speed stop is factory adjusted. Do not
adjust - damage may resulL
IMPORTANT'; Never tamperwiththe engine
governor, which is factory set for proper
engine speed. Overspeeding the engine
above the factory high speed setting can be
dangerous. If you thinkthe engine-governed
high speed needs adjusting, contact a Sears
or other qualified service center, which has
proper equipment and experience to make
any necessary adjustments,
Idle Speed r _ ''"_."'°'" Throttle
Screw _--_ Lever
C
Idle Mixture Valve _
With Limiter
26