Sears Craftsman 917.256451 Owner's Manual page 80

SERVICE AND ADd
TO A©JUST CARBU_3ETOR (See Fig. 28)
The carburetor isas been p_eset at the facto_j and adjust-
merit should not be secessary. However, minor adjust °
merit may be _'equired to compensate fordifferences in fuel,
tempe_ature_ a!titude or load. If the carburetor does need
adiustment, p_oceed as follows:
!n ge,qecai, tumi_g idle mixture valve in (clockwise) de-
c re _s:ses t he suppiy of fuei to the engine giving a leaner fuel/
ai_"m,i×t_.._re. T urning the idle mix:ture valve out (counter-
c!ockwis ::).incre ¢_ses the supp:iy of fuel to the; engine giving
a richer fuei/a;_ mi;<ture_
!WiSOF:_iTA_4T_ D AMA(_£ TO THff NEEDLE VALVE AND
1'HE !}_EAT!N CAHBUf::_.L{TOR MAY RESULT !F SCREW 1S
TU :I:NiLDtN TOO TIGHT,
PRELIM!:NARY SETTING -
_, Aii° clean.,.ir _ss embty paust be assembled to the ca_bu_,
_"eto_ w! ;_n _ _..:_:kin _.]ca_'bui-eto_ _adjustments,
_, Be sure the th_"ottle conti-oi cabie is adjusted properly
(see above).
With en{_iir::e off turn idle mixtiye valve i_,_(clockwise)
ck)s;__git finger tigY£ and titan turn otat (countercleck-
F!NAL S_I}TFTi:NG -
_ Start engine and allow to warm fo_ _five minutes. Make
iinai adit._strt_e,:_ts with engine i-urming and shift!motion
controi ievet" in _ eub'at (N) position.
,_ _4ove throt<Jecontrol ieve_ to siow(<_s_) positieno With
_inger_;]ii!ta1:e a __dho!d th_ottle !ever against idle speed
screw, sum idie speed screw !:o 8.1:rain !'750 RPM_
.,, VVb_:ie:stii: hold:r:f: th_ott!e !eve:" sga:nst :die speed
sc_'ew turn idle mixture .iaive :_-_ (ciockwise) until am
ji£':,e b _:_g[ns to <fie a_"_.d if:an turn ,s:,_ut (cou nterciockvd se)
:._n:::ii es,:_ff_e _.ms _'oufS";. -rum :,,'alva _o a Oeird: midway
beb_vees those two positions. R@ease th_'ottb ieve[o
ENTS
A,..,._LERA __O,(_T_o T
o Move throttie control !ever from slow (_) to fast (@)
position. If engine hesitates or dies, turn idle mixture
valve out (counterclockwise) 1/8 tu m. Repeat tes_ and
continue to adjust, if necessa% untii engine acceler-
ates smoothlyo
High speed stop is factom/ adjusted. Do not adjust -
damage may resulto
_MPORTANT: NEVER TAMPER WITH THE ENGINE
GOVERNOR, WHICH IS FACTORY SET FOR PROPER
ENG_NESPE_D, OVERSPEEDING THE ENGINE ABOVE
i-HE FACTORY HIGH SPEED SETTING CAN BE
DANGEROUS° IF YOU THINK THE ENGtNE_GOVERNED
i-IIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEAREST AUTHORIZED SERVICE OENTERi
DEPARTMENT, WHICH HAS PROPER EQUIPMENT AND
EXPERIENOE TO MAKE ANY NECESSARY
ADJUSTMENTS.
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_DLiI_ ?_I_XTU_8 VALVE
_:iG_28
24