Sears 917.252641 Owner's Manual page 13

EVERY _P_) HOURS .... CONTINUED
2_ CHANGE ENGINE OIL
The best time to change Engine Oil is at the end of a days
operation when all dirt and foreign material is suspended
in the hot Oil Refer to Fig 23
EVE.V 5@.OU.S
1, CLEAN ENGINE COOLING SYSTEM
Grass, chaff or dirt may clog the air cooling system, espe-
cially after prolonged service cutting dry grasses To avoid
overheating and engine damage, remove the Blower Housing
and clean the area shown in Fig 25 - Inset
1
WEAR SAFETY GLASSES 1F USING COM- I
PRESSED AIR,
I
2. MUFFLER
Do not operate the tractor without a Muffler (Fig 25) or
tamper with the exhaust system Damaged Mufflers or
spark arresters could create a fire hazard, Inspect periodi-
cally and replace if necessary If your engine is equipped
with a spark arrestor screen assembly, remove every 50
hours for cleaning and inspection Replace if damaged
EVE. ' .OU.S
Replace Spark Plug at the beginning of each season or every
100 hours, whichever comes first Gap should be set at 030
inch (Fig 26)
[v[.v 3®@.ou.,
REPLACE AIR CLEANER ELEMENT
Refer to page 10. The Air Cleaner Element is listed on page
39, Key No_ 4.
.o. ,.16 mi!i
/ ,
' ' r'H'l '1 ' '1 i iiii
AS NEEDED
1. CARBURETOR ADJUSTMENT
Never attempt to change maximum engine speed, This is
preset at the factory and should only be changed by a quali-
fied service technic;an who has the necessary equipment
a TO ADJUST CARBURETOR ,, Turn Needle Valve
clockwise until it just closes (Fig 27- Inset)
NOTE: VALVES MAY BE DAMAGED BY TURNING
THEM TOO FAR.
Now open Needle Valve 1 - 1/2 turns Close Idle Valve in
same manner and open I - 1/4 turns, This initial adjustment
will permit the engine to be started and warmed up prior to
fina! adjustment_
........................... l
REFER TO "STARTING THE TRACTOR'"
PAGE 5,
FINAL ADJUSTMENT - Place throttle control in
"FAST" position (Fig. 12) Turn Needle Valve in until
engine slows (clockwise .. lean mixture). Then turn it out
past smooth operating point (rich mixture).. Now turn
Needle Valve to midpoint between rich and lean., Next
adjust idle RPM. Rotate Throttle counterclockwise and
hold against Stop. Adjust Idle Speed Adjusting Screw to
obtain 1750 RPM Holding Throttle against Idle Stop.
turn Idle Mixture Valve in (lean) and out (rich). Set at
midpoint between rich and lean Re-check idle RPM Re-
lease throttle If engine wil! not acceterateproperly. _he
carburelor should hi._ [e-adjustud. usually lo a slighlly
richer mixture