Engine, Service and adjustments – Craftsman 917.255520 User Manual
Page 24
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SERVICE AND ADJUSTMENTS
ENGINE
TO ADJUST THROTTLE CONTROL CABLE
(See Fig. 32)
The throttle control has been preset at the factory and ad
justment should not be necessary. Check adjustment as
described below before loosening cable if adjustment is
necessary, proceed as follows:
*
With engine not running, move throttle control lever
from "SLOW" to "CHOKE" position Slowly move lever
from "CHOKE" to "FAST" position
•
Check that hoies "A" in governor control lever and hoie
in governor plate line-up. If holes "A" are not aligned,
loosen clamp screw and move throttle cable until holes
are aligned. Tighten damp screw securely.
FIG. 32
TO ADJUST CARBURETOR (See Fig. 33;
The carburetor has been preset at the factory and adjust
ment should not be necessary. However, minor adjust
ment may be required to compensate for differences in fuel,
temperature, altitude or load. If the carburetor does need
adjustment, proceed as follows:
In general, turnig idle mixture valve
in
(clockwise) de
creases the supply of fuel to the engine giving a leanerfuel/
air mixture, Turning the idle mixture valve
out
(counter
clockwise) increases the supply of fuel to the engine givirig
a richer fuei/air mixture.
IMPORTANT: DÁMAGETOTHENEEDLEVALVE AND
THE SEAT IN CARBURETOR MAY RE
SULT IF SCREW IS TURNED IN TOO
TIGHT,
PRELIMINARY SETTING-
♦ Air cleaner assembly must be assembled to the carbu
retor when making carburetor adjustments,
« Be sure the throttle control cable is adjusted properly
(see above),
' With engine off turn idle mixture valve
in
(clockwise)
closing it finger tight and then turn out (counterciock-
wise) 1 full turn.
FINAL SETTING -
•
Start engine and allow to warm for five minutes. Make
final adjustments with engine running and shift/motlon
control lever in “NEUTRAL" position,
•
Move throttie control lever to "SLOW" position. With
finger, rotate and hold throttle lever against idle speed
screw. Turn idle speed screw to attain 1750 RPM.
•
While still holding throttle lever against idle speed
screw, turn idle mixture valve in (clockwise) until en
gine begins to die and then turn
out
(counterclockwise)
until engine runs rough. Turn valve to a point midway
between those two positions, Release throttle lever.
ACCELERATION TEST -
•
Move throttle control lever from "SLOW" to "FAST"
position. If engine hesitates or dies, turn Idle mixture
valve
out
(counterclockwise) 1/8 turn, Repeattestand
continue to adjust, if necessary, until engine acceler
ates smoothly.
High speed stop Is factory adjusted. Do not adjust -
damage may result.
IMPORTANT: NEVER TAMPER WITH THE ENGINE
GOVERNOR, WHICH tS FACTORY SET
FOR PROPER ENGINE SPEED. OVER
SPEEDING THE ENGINE ABOVE THE
FACTORY HIGH SPEED SETTING CAN
BE DANGEROUS, IF YOU THINK THE
ENGINE-GOVERNED HIGH SPEED
NEEDS ADJUSTING, CONTACT YOUR
NEAREST
AUTHORIZED
SERVICE
CENTER, WHICH HAS PROPER EQUIP
MENT AND EXPERIENCETOMAKEANY
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