MAINTENANCE AND REPAIR INSTRUCTIONS
Adjust Idle Speed Screw
WARNING: To prevent serious personal injury, make sure the cutting attachment has stopped rotating before you turn it off and set it down.
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 throttle trigger and let the engine idle. If the engine stops, insert a small phillips screwdriver in between the Air Filter Cover and the Engine Cover (Fig. 29). Turn the idle speed screw in, clockwise, 1/8 of a turn at a time (as needed) until the engine idles smoothly.
NOTE: The cutting attachment should not rotate when the engine idles.
4.Remove the engine cover (Fig. 30).
5.Clean dirt from around the rocker arm cover. Remove the screw holding the rocker arm cover with a large flat blade screwdriver or Torx T- 25 bit (Fig. 31). Remove the rocker arm cover and gasket.
6.Pull the starter rope slowly to bring the piston to the top of its travel, (known as top dead center). Check that:
•The piston is at the top of its travel while looking in the spark plug hole (Fig. 32)
Rocker
Arm
Cover
Spark
Plug
Hole
Fig. 31
3.If the cutting attachment rotates when the engine idles, turn the idle speed screw counterclockwise 1/8 of a turn at a time (as needed), until the attachment stops turning.
WARNING: The cutting attachment may spin during idle speed adjustments. Wear protective clothing and observe all safety instructions to prevent serious personal injury.
Checking the fuel, 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 service dealer.
ROCKER ARM CLEARANCE
This requires disassembly of the engine. If you feel unsure or unqualified to perform this, take the unit to a Sears or other qualified service dealer
NOTE: Inspect the valve to rocker arm clearance with a feeler gauge after the first 10 hours of operation and every 25 hours of operation.
•The engine must be cold when checking or adjusting the valve clearance.
•This task should be performed inside, in a clean, dust free area.
1.Remove the six (6) screws on the back of the engine cover with a
2.Disconnect the spark plug wire.
3.Clean dirt from around the spark plug. Remove the spark plug from the cylinder head by turning a 5/8 in. socket counterclockwise.
View Of The Rear Engine Cover
Remove | Remove |
Screws | Screws |
•Both rocker arms move freely, and both valves are closed. If these statements are not true, repeat this step.
7.Slide the feeler gauge between the rocker arm and the valve return spring. Measure the clearance between the valve stem and rocker arm (Fig. 32 & 33). Measure both the intake and exhaust valves.
| Adjusting Nuts |
Rocker Arms | INTAKE |
|
EXHAUST
Feeler Gauge
Spark Plug
Hole
Fig. 32
The recommended clearance for both intake and exhaust is
.003
.005 in. (0.127 mm) feeler gauge. The feeler gauge should slide between the rocker arm and valve stem with a slight amount of resistance, without binding. See Figures 31 and 32.
8.If the clearance is not within specification:
a.Turn the adjusting nut using a 5/16 inch (8 mm) wrench or nut driver (Fig. 33).
•To increase clearance, turn the adjusting nut counterclockwise.
•To decrease clearance, turn the adjusting nut clockwise.
b.Recheck both clearances, and adjust as necessary.
9.Reinstall the rocker arm cover using a new gasket. Torque the screw to
10.Check the spark plug and reinstall. See Replacing the Spark Plug.
11.Replace the spark plug wire.
Fig. 30
12