Craftsman 247.885680 - Manual (Page 20)

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SERVICE & ADJUSTMENT
If adjustment is necessary, loosen the lock nut on the
traction drive cable and thread the cable in o ■ out as
necessary. Tighten the lock nut to secure the cable
when correct adjustment is reached. Reassemble the
frame cover.
•
NOTE: If you placed plastic under the gas ■^ap, be
certain to remove it.
FIGURE 24.
AUGER CLUTCH ADJUSTMENT
To adjust the auger clutch, refer to Final Adjustment
section of Assembly Instructions.
SHIFT ROD ADJUSTMENT
To adjust the shift rod, remove the hairpin clip and flat
washer which secure the shift rod to the sf ift arm
assembly. Refer to figure 8 . Adjust as specified in
Assembly Instructions.
CARBURETOR ADJUSTMENT
A
WARNING: IF ANY ADJUSTMENT« ARE
MADE TO THE ENGINE WHILE THE
ENGINE IS RUNNING (E.G. CAREIURE-
TOR), KEEP CLEAR OF ALL MOVING
PARTS. BE CAREFUL OF HEATED SUR­
FACES AND MUFFLER.
Minor carburetor adjustment may be required lo com­
pensate for differences in fuel, temperature, altitude
or load.
Never attempt to change maximum engine spead. It is
pre-set at the factory and should be changed anly by
a qualified service technician who has the necessary
equipment.
5 H.P. ENGINE
Idle Speed Adjustment. This screw is located on top
of the carburetor and contacts the throttle. To initially
pre-adjust this speed, back out the screw, then turn in
until the screw just touches the throttle lever, then turn
screw in 1 turn. When the engine is run, the final idle
R.P.M. can be adjusted with a tachometer.
Idle and Main Adjustment. Turn these adjustment
screws in finger tight, then back them out to the pre­
set figure on the chart.
TECUMSEH CARBURETOR PRE-SETS
ENGINE MAIN IDLE
MODELS PRE-SET PRE-SET
5 H.P. 1-1/4 1
Final Carburetor Adjustments
Allow engine to warm up to a normal running temper­
ature. With engine running at maximum recom­
mended R.P.M., loosen main adjustment screw until
engine starts to cut out. Then turn screw opposite
direction until engine starts to cut out. Note the num­
ber of turns from one extreme to the other. Loosen
screw to a point midway between the extremes.
After the main system is adjusted, move the speed
control lever to the idle position and follow the same
procedure for adjusting the idle system.
Test the engine by running it under a normal load.
The engine should respond to load pick-up immedi­
ately. An engine that “dies” is too lean.
An engine which ran rough before picking up the load,
is adjusted too rich.
If adjustment seems too “touchy” check float for prop­
er setting and for sticking.
8 H.P. ENGINE
Preset the carburetor by turning both idle and main
adjustment screw closed (clockwise) fingertight. Open
the main adjustment screw
2 turns (counterclockwise)
and the idle adjustment screw 1 -3/4 turns.
Generally, the engine will perform well with these set­
tings. If further adjustment is required, perform the fol­
lowing adjustments with the engine running and fully
warmed up.
With speed control lever at idle or slow speed, turn
the idle adjustment screw slowly, clockwise
1/8 turn at
a time until the lean drop off point is reached. (The
engine will miss and run erratically due to lack of fuel.)
Now turn the screw counterclociwise 1/4 to 3/8 turn
from that position. This will be the best setting.
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