Craftsman 247.797852 Owner's Manual page 14

Pi
Sharp
of
Torque
Wrenctl
Allen
Screws
e When reassembling the blade, tighten to between
550 and 650 inch pounds, or lacking torque
wrench, tighten securely
FLAILS
The flails, located inside the housing, may be
reversed when they become dull It is suggested that
this procedure be performed by your nearest Sears
Service Department
CARBURETOR A DJUSTMENT
WARNING: IF ANY ADJUSTMENTS ARE
MAUE TO THE ENGINE WHILE THE
ENGINE IS RUNNING (E.G. CARBURE-
TOR), KEEP CLEAR OF ALL MOVING
PARTS. BE CAREFUL OF HEATED SUR-
FACES AND MUFFLER.
FIGURE 2O,-Model 247.797853 Shown
e Loosen the two hand knobs and cupped washers
which secure the chute deflector, arrd raise the
chute deflector
e Insert a 1/2" or 3/4" diameter pipe through the flail
screen into the impeller to keep it from turning, or
remove the flail screen and insert a piece of wood
(2 x 4) into the chute opening
e Model 247.797853 only: Remove the two outside
screws on the blade, using a 3/16" allen wrench
and a 1/2" wrench
e Remove the blade by removing the center bolt, lock
washer and flat washer
NOTE: Use caution when removing the blade to avoid
contacting the weld bolts on the housing
e When sharpening the blade, follow the original
angle of grind as a guide It is extremely important
that each cutting edge receives an equal amount of
grinding to prevent an unbalanced blade. An unbal-
anced blade will cause excessive vibration when
rotating at high speeds and may cause damage to
the unit.
e The blade can be tested for balance by balancing it
on a round shaft screwdriver or nail Remove metal
from the heavy side until it is balanced evenly See
figure 21
Na. \ /
f ,,
/
Bl!de '__1" --_j_
FIGURE 21,
Minor carburetor adjustment may be required to com-
pensate for differences in fuel, temperature, altitude
or load
NOTE: A DIRTY AIR CLEANER WILL CAUSE
ENGINE TO RUN ROUGH BE CERTAIN AIR
CLEANER IS CLEAN AND ATTACHED TO THE
CARBURETOR BEFORE ADJUSTING CARBURE-
TOR DO NOT MAKE UNNECESSARY ADJUST-
MENTS FACTORY SETTINGS ARE SATISFACTO-
RY FOR MOST APPLICATIONS AND CONDITIONS.
/
Never attempt to change maximum engine speed It is
pre-set at the factory and should be changed only by
a qualified service technician who has the necessary
equipment
The carburetor may need re-adjusting if engine lacks
power or does not idle properly If adjustments are
needed, proceed as follows
e Close needle valve (see figure 22) clockwise
( f-* ) finger tight only. Forcing may cause damage
Then open 1-1/2 turns counterclockwise ( _ )
e Start engine and allow to warm for five minutes
e With throttle in FAST position, close needle valve
clockwise ( ,_ ) until engine starts to lose speed
(lean mixture) Then slowly open needle valve
counterclockwise (f',) until engine JUST BEGINS
to run unevenly This mixture should be rich
enough for best performance under load.
e Place throttle control in IDLE position
If engine idles, no further adjustment is necessary
If engine idles too fast, turn idle speed adjusting
screw counterclockwise ( _ ) until slower speed is
obtained
If engine dies, turn idle speed adjusting screw 1/4
turn clockwise ( ,_ ). Place throttle control in FAS]_'
position and restart engine
Move throttle control to IDLE position_ If engine
does not idle, repeat step c
14