Craftsman 917.295550 - Manual (Page 19)

SERVICE AND ADJUSTMENTS
ENGINE
TO ADJUST THROTTLE CONTROL CABLE
(See Fig. 29)
• Loosen cable clamp screw to allow cable to move.
• Move throttle control lever on upper handle to “FAST"
position.
• Pull throttle cable out until engine bellcrank is back as
far as it will go.
• Hold cable in this position and tighten clamp screw
securely.
FINAL SETTING
• Start engine and allow to warm for five minutes. Make
final adjustments with engine running at idle and drive
control bar in "DISENGAGED" position.
• With throttle control lever in "SLOW" position, turn idle
needle valve in (clockwise) until engine begins to die
then turn out (counterclockwise) until engine runs
rough. Turn valve to a point midway between those two
positions.
IDLE RPM ADJUSTMENT
• To adjust idle RPM, rotate throttle linkage counter­
clockwise and hold against stop while adjusting idle
speed adjusting screw to obtain 1750 RPM, Release
throttle linkage.
ACCELERATION TEST
TO ADJUST CARBURETOR (See Fig. 30)
The carburetor has a high speed jet and has been preset at
the factory and adjustment should not be necessary. How­
ever, minor adjustments 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 idle needle valve in (clockwise)
decreases the supply of fuel to the engine giving a leaner
fuel/air mixture. Turning the needle valve out (counter­
clockwise) increases the supply of fuel to the engine giving
a richer fuel/air mixture.
IMPORTANT: DAMAGE TO THE NEEDLES AND THE
SEATS IN CARBURETOR MAY RESULT IF SCREWS
ARE 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 property
(see above).
• With engine off, turn idle needle valve in (clockwise)
closing it finger tight and then turn valve out (counter­
clockwise) 1-1/2 turns.
• Move throttle control lever from “SLOW” to "FAST"
position. If engine hesitates or dies, turn needle valve
out (counterclockwise) 1/8 turn. Repeat test and
continue to adjust, If necessary, until engine acceler­
ates smoothly.
High speed stop is factory adjusted. Do not adjust or
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. IFYOUTHINKTHEENGINE-GOVERNED
HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEAREST SEARS SERVICE CENTER, WHICH HAS
PROPER EQUIPMENT AND EXPERIENCETO MAKE ANY
NECESSARY ADJUSTMENTS,
19