Craftsman 917.270770 - Manual (Page 26)

Remove air cleaner cover, filter and car­
tridge plate to expose carburetor choke
(see “AIR FILTER" in the Customer
Responsibilities section of this manual).
Choke should be closed. If it is not,
loosen casing clamp screw and move
choke cable until choke is completely
closed. Tighten casing clamp screw se­
curely.
Reassemble air cleaner.
Ctamp Screw
Quarter
Circi'
Choke Closed
Caang a pi p
Clamp Screw '
Choke
Lever
TO ADJUST CARBURETOR
The carburetor has been preset at the fac­
tory and adjustment should not be neces­
sary. 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 the mixture screw in
(clockwise) decreases the supply of fuel to
the engine giving a leaner fuel/air mixture.
Turning the mixture screw out (counter­
clockwise) increases the supply of fuel to
the engine giving a richer fuel/^r mixture.
IMPORTANT; Damage td the needles and
the seats in carburetor may result if screw
is turned in too tight.
PRELIMINARY SETTING-
* Be sure you have a clean air'filter, and
the throttle control cable and choke are
adjusted properly (see above).
• With engine off turn idle mixture screw
in (cloclwise) closing it finger tight and
then turn out (counterclociw'ise) 1-1/4
to 1-1/2 turns.
FINAL SETTING-
• Start engine and allow to warm for five
minutes. Make final adjustments with
engine running and shift/ motion control
lever in neutral (N) position.
• With throttle control lever in slow posi­
tion, hold throttle lever against idle
speed screw and adjust idle speed
screw to obtain 1200 to 1400 RPM.
• While still holding throttle lever against
idle speed screw, turn idle mixture
screw In (clockwise) until engine begins
to die and then turn out (counterclock­
wise) until engine runs rough. Turn
screw to a point midway between those
two positions.
• Continue to hold throttle lever against
idle speed screw and adjust idle speed
screw to obtain 900 to 1200 RPM. Re­
lease throttle lever.
ACCELERATION TEST -
• Move throttle control lever from slow to
fast position. If engine hesitates or dies,
turn idle mixture screw out (counter­
clockwise) 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. Overspeeding the
engine above the factory high speed set­
ting can be dangerous. If you think the
engine-governed high speed needs
adjusting, contact your nearest authorized
service center/department, which has
proper equipment and experience to make
any necessary adjustments.
.Idle Speed
Screw
Idle Mixture
Screw
Throttle Lever
Idle Speed
Screw.
Throttle
Lever
Idle Mixture
Screw
26