Craftsman 3One 917.252531 Owner's Manual page 27

SERVICE AND ADJUSTMENTS
ENGINE
TO ADJUST THROTTLE CONTROL CABLE
(See Fig. 33)
The throttle control has been preset at the factory and
adjustment 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 (N) position. Slowly move
lever from choke (N) to fast (,€_) position.
° Checkthat holes"A" in governorcontrol lever and hole
in governor plate line-up_ If holes "A" are Tot aligned,
loosen clamp screw and move throttle cable until holes
are aligned. Tighten clamp screw securely.
GOVERNOR GOVERNOR
CONTROL LEVER CONTROLPLATE
HOLES "A" CLAMP THROTTLE
SCREW CABLE
FIG. 33
TO ADJUST CARBURETOR (See Fig. 34)
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 Ioado tf the carburetor does need
adjustment, proceed as follows:
In general, turning idle mixture valve in (clockwise) de-
creases the supply of fuel to the engine giving a leaner fuel/
air mixture. Turning the idle mixture valve out (counter-
clockwise) increases the supply of fuel to the engine giving
a richer fuel/air mixture.
IMPORTANT: DAMAGE TO THE NEEDLE VALVE AND
THE SEAT 1NCARBURETOR MAY RESULT IF SCREW IS
TURNED IN TOO TtGHT.
PRELIMINARY SETTING
• Aircleaner assembly must i_'eassembled 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 itfinger tight and then turn out (counterclock-
wise) I full turn.
FINAL SETTING -
- Start engine and allowto warm for five minutes. Make
final adjustments with engine running and shift/motion
control lever in neutral (N) position.
° Move throttle 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) untd en-
gine beg!ns 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 -
o Move throttle control lever from slow (._=_)to fast (,_)
position. If engine hesitates or dies, tum idle mixture
valve out (counterclockwise) 1/8 turn. Repeat test and
continue to adjust, if necessary, until engine acceler-
ates smoothfy.
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 SETTING CAN BE
DANGEROUS.. tF 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
THROTTLE IDLE SPEED
IDLE MIXTURE
VALVE
FIG. 34
27