Craftsman 316.794791 Operator's Manual page 12

CARBURETOR ADJUSTMENT
The idle speed of the engine is adjustable. An idle adjustment screw
is between the air filter cover and the engine starter housing (Fig. 24).
Idle Adjustment
Screw
4. Replace cracked, fouled or dirty
spark plug. Set the air gap at
0.025 in. (0.635 mm) using a
feeler gauge (Fig. 25).
5. Install a correctly-gapped spark 0.025 in.
plug in the cylinder head. Turn (0.635 mm.)
the 5/8 in. socket clockwise
until snug. _r
If using a torque wrench torque to: &
110-120 in.olb. (12.3-13.5 Nom)
/
Do not over tighten. Fig. 25
SPARK ARRESTOR MAINTENANCE
Inspect the spark arrestor after every 50 hours of operation.
1. Stop the engine and allow it to cool. Remove the four (4) screws
on the back of the engine cover with a Flat-head or T-20 Torx
screwdriver (Fig. 26).
Remove Remove
\ Screws
Fig. 24
NOTE: Careless adjustments can seriously damage your unit. An
authorized service dealer should make carburetor adjustments.
Check Fuel
Old and/or improperly mixed fuel is usually the reason for improper unit
performance. Drain and refill the tank with fresh, properly-mixed fuel
prior to making any adjustments. Refer to Oil and Fuel Information.
Clean Air Filter
The condition of the air filter is important to the operation of the unit.
A dirty air filter will restrict air flow. This is often mistaken for an out
of adjustment carburetor. Check the condition of the air filter before
adjusting the idle speed screw. Refer to Air Filter Maintenance.
Adjust Idle Speed Screw
If, after checking the fuel and cleaning the air filter, the engine still
will not idle, adjust the idle speed screw as follows:
1. Start the engine and let it run at a high idle for a minute to
warm up. Refer to Starting/Stopping Instructions.
2. Release the trigger lock and let the engine idle. If the engine
stops, insert a small phillips in between the Air Filter Cover
and the Engine Cover (Fig. 24). Turn the idle speed screw in,
clockwise, 1/8 of a turn at a time (as needed) until the engine
idles smoothly.
Checking the fuel mixture, cleaning the air filter, and adjusting the
idle speed should solve most engine problems. If not and all of the
following are true:
• the engine will not idle
• the engine hesitates or stalls on acceleration
• there is a loss of engine power
Have the carburetor adjusted by a Sears or other qualified dealer.
REPLACING THE SPARK PLUG
Use a Champion #RDZ4H or a replacement part #753-05784 spark
plug. The correct air gap is 0.025 in. (0.635 mm.). Remove the plug
after every 25 hours of operation and check its condition.
1. Stop the engine and allow it to cool.
2. Grasp the plug wire firmly and pull the cap from the spark plug.
3. Clean dirt from around the spark plug. Remove the spark plug
from the cylinder head by turning a 5/8 in. socket
counterclockwise.
WARNING:
Do not sand blast, scrape or clean I
electrodes. Grit in the engine could damage the
I
cylinder.
Fig. 26
2. With a Torx T-27 bit, remove the 2 screws attaching the
mufflerr to the engine (Fig. 27).
"1"-27 Screws
Muffler
Fig. 27
3. With a flat blade screwdriver or Torx T-20 bit, remove the screw
attaching the spark arrestor cover to the muffler (Fig. 28, A).
A
"1"-20Screw
Spark Arrestor Cover
Fig. 28
Spark
B
Arrestor
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