Craftsman DYT 4000 917.273642 - Manual (Page 28)

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. The limiter cap
cannot be removed without breaking the
adjusting needle.
The carburetor has been preset at the
factory and adjustment should not be nec­
essary. 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 mix­
ture. Turning the idle mixture valve out
(counterclockwise) increases the supply
of fuel 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 -
1. Air cleaner assembly must be assem­
bled to the carburetor when making
carburetor adjustments.
2. Be sure the throttle control cable is
adjusted 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
tion. With finger, rotate and hold throttle
lever against idle speed screw. Turn
idle speed screw to attain 1750 RPM.
3. While still holding throttle lever against
idle speed screw, turn idle mixture
valve full travel clockwise then coun­
terclockwise until engine runs rough.
Turn 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 result.
IMPORTANT: Never tamper with the
engine governor, which is factory set
for proper engine speed. Overspeed­
ing the engine above the factory high
speed setting can be dangerous. If you
think the 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.
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