Carburetor; Mixture Adjustment; Checking Adjustment; Throttle Control Cable Adjustment - Craftsman 917.298231 Owner's Manual

SERVICE AND ADJUSTMENT
CARBURETOR
NOTE: A dirly Air Cleaner will cause tile Engine to run
rough, Be sure Air Cleaner is clean before adjustments
are made Faclory seltings are satisfactory for most ap-
plications and condilions If adjuslments are needed, pro-
ceed as Iollows:
Never attempt to change maximum Engine speed. This
is preset at the factory and should only be changed by a
qualified service technician who has the necessary
equipment The Carburetor mixture may need re-adjust-
ing if Engine lacks power or does not idle properly,
MIXTURE ADJUSTMENT'
• Turn Needle Valve (Fig, 26) clockwise (,,_) until it just
closes. Valve may be damaged by turning Needle Valve
in too far
• Open Needle Valve 1-1/2 turns counterclockwise 0_)
This initial adjustment will permit the Engine to be
started and warmed up prior to final adjustment
• Start the Engine_ Allow Engine to warm up for about 5
minutes before preceeding_
• Place Throttle Control in "IDLE" position
• Turn Needle Valve in until Engine slows (clockwise
(,"--()lean mixture)
THROTTLE THROTTLE
LINKAGE STOP
• Next turn Needle Valve out past smooth operating poiN
until Engine runs unevenly (counterclockwise (:,_',)rk
mixlure)
• Now lurn Needle Valve to the midpoint between rich
and lean so the Engine runs smoothly
IDLE RPM ADJUSTMENT
• To adjust Idle RPM, Rotate Throttle Linkage counter-
clockwise F'_) and hold against stop while adjusting
Idle Speed Ad ustng Screw _o obtain 1750 RPM Re-
lease Throttle Linkage
CHECKING ADJUSTMENT
• Test the Engine by tilling If Engine dies out, it usually
indicates that the mixture is slightly lean and it may be
necessary to open (_"', the Needle Valve slightly to
provide a richer mixture This richer m xture may cause
a slight unevenness in idling
THROTTLE CONTROL CABLE ADJUSTMENT
CAUTION: NEVER TAMPER WITH THE ENGINE GOV-
ERNOR, WHICH IS FACTORY SET FOR
PROPER ENGINE SPEED
• Loosen Throttle Cable Adjusting Screw
• Wilh Throttle Conlrol in "FAST" position and Cable con-
nected lo Bellcrank, pull Cable backward through Screw
until Bellcrank is as far rea_ard as it will go
• Tighten Adjusting Screw
MUFFLER PLUG
WIRE
IDLE SPEED NEEDLE
ADJUSTING VALVE
SCREW
THROTTLE
CABLE
THROTTLE
CABLE
ADJUSTING
SCREW
FIGURE 26
18