Carburetor Adjustment - Craftsman 768.884900 Owner's Manual

Carburetor Adjustment
Never make unnecessary adjustments to the carburetor.
The carburetor was set at the factory to operate efficiently
for most applications (from 0 to 4000 feet above sea
level). However, if adjustments are required, proceed as
follows:
IMPORTANT: When adjusting the carburetor, best re
sults will be obtained if the adjustments are made on a
warm engine. During carburetor adjustments, do not
force screw into the seat. DO NOT remove carburetor
cover. Access holes in cover will allow adjustments to be
made with a screwdriver.
1. Close the high-speed and the idle adjustment needles
finger tight. Do not force. Then open high speed ad
justment needle V/2 turn and idle adjustment needle
V/2 turn (see Figure 33).
2. Start the engine as described in paragraph To Start
Engine.
3. For high speed adjustment move the throttle lever to
FAST position and then turn the high speed adjusting
needle in or out 1/8 turn at a time until engine runs
smoothly. NOTE: Allow several seconds between
each adjustment for the engine to react to the new
carburetor settings.
4. When the engine is running smoothly, turn the high
speed needle out 1/8 turn counterclockwise. This
may add a slight roughness to the engine which is
advisable for underload operation.
5. For idle adjustment, move the throttle lever to SLOW
position. Turn the idle adjustment needle in or out 1/8
turn at a time until engine idles smoothly. NOTE:
Allow several seconds between each adjustment for
the engine to react to the new carburetor settings.
IDLE
ADJUSTMENT NEEDLE
(CIom finger tight only)
HIGH-SPEED ADJUSTMENT NEEDLE
(Oottflngtrtight only) FIGURE 33
A CAUTION A
Never tamper with engine governor which is factory set
for proper engine speed. Over-speeding engine above
factory high speed setting can be dangerous. If you
think the engine governed high speed needs adjusting,
contact your nearest SEARS Service Center who has
the proper equipment and experience to make any ne
cessary adjustments.
IMPORTANT
Ifthe carburetor is adjusted in temperatures above 45° F,
such as in a heated workshop, it may be necessary to set
the carburetor slightly richer. This will compensate for
operation in cold temperatures.
After the carburetor has been adjusted and allowed to
react to the new setting (see Carburetor Adjustment)
open the high speed adjusting needle an additional 1/16
to 1/8 turn.
DO NOT EXCEED 1/8 TURN.
This will add a slight roughness to the engine when run
in temperatures above 45° F.
For best results, carburetor adjustments should be made
in temperatures that the snowblower will be most used
in.
Engine Servicing
For any major engine adjustment or servicing during the
engine warranty period, contact your nearest Sears Ser
vice Dept.
For prompt and efficient sen/ice, please furnish the en
gine model, type and trim number of your engine.
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