Sears 580.768050 - Manual (Page 14)

Clean / Replace Spark Plug
Replace the spark plug yearly or every 100 hours of
operation, whichever comes first.
A CAUTION: Disconnect spark plug wire from
spark plug and keep wire away from spark plug.
Clean area around spark plug.
Remove spark plug form the cylinder head.
Replace spark plug if the electrodes are pitted,
burned or porcelain is cracked. For replacement
use Champion RC12YC or equivalent.
Check electrode gap with wire feeler gauge and set
gap to 0.76mm {.030 inches), if necessary.
Install a correctly gapped spark plug into the
cylinder head, tighten securely.
If you think your carburetor needs adjusting, see your
nearest Sears Sen/ice Center. Engine performance
may be affected at altitudes above 5000 feet. For
operation at higher elevations, contact your nearest
Sears Service Center.
Adjusting Valve Clearance
After the first fifty (50) hours of operation, you should
adjust the valve clearance in the engine.
Important If you feel uncomfortable about doing this
procedure or you don’t have the proper tools, please
take your cleaning system In to the nearest service
center to have the valve clearance adjusted. This is a
very important step to insure the longest life for your
engine.
To adjust vah№ clearance:
• Make sure the engine is at room temperature.
• Make sure that the spark plug wire is removed from
the spark plug and out of the way.
• Remove the breather tube from the valve cover.
• Remove the four screws attaching the valve cover
with a #2 or 3 Phillips screwdriver.
Make sure the piston is at Top Dead Center (TDC)
of its compression stroke (both valves closed). To
get the piston at top dead center, pull on the recoil
handle slowly watching the piston trough the spark
plug hole. As you pull on the recoil handle the ,
piston should move up and down. The piston is put
Top Dead Center when it is up as high as it can go.
FMlar Q u « 9 »
Tigbt«n Jam Nut to
65-85in-lba
Allan Wraneh
Looaan Jam Nut
Using a 10mm wrench, loosen the rocker arm jam
nut. Use an 8mm alien wrench to turn the pivot ball
stud white checking clearance between the rocker
arm and the valve stem with a feeler gauge.
Correct clearance is 0.002-0.004 inch (0.05­
0.1mm). Note: You must hold the rocker arm jam
nut in place as you turn the pivot ball stijd.
When valve clearance is correct, hold the pivot ball
stud in place with the alien wrench and tighten the
rocker arm jam nut. Tighten the jam nut to 65-85
inch-pounds torque. After tightening the jam nut,
recheck valve clearance to make sure it did not
change.
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