MAINTENANCE AND REPAIR INSTRUCTIONS
WARNING: The cutting attachment may spin during idle speed adjustments. Wear protective clothing and observe all safety instructions to prevent serious personal injury.
CARBURETOR ADJUSTMENT
The idle speed of the engine is adjustable. An idle adjustment screw is reached though a hole in the top of the engine cover (Fig. 34).
NOTE: Careless adjustments can seriously damage your unit. An authorized service dealer should make carburetor adjustments.
Check Fuel
Old fuel is usually the reason for improper unit performance.
Drain and refill the tank with fresh 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 throttle trigger and let the engine idle. If the engine stops, insert a small phillips or flat blade screwdriver into the hole in the air filter/muffler cover (Fig. 34). 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, 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 an authorized service dealer.
ROCKER ARM CLEARANCE
This requires disassembly of the engine. If you feel unsure or unqualified to perform this, take the unit to an authorized service center.
WARNING: To prevent serious personal injury, make sure the cutting attachment has stopped rotating before you turn it off and set it down.
NOTE: Inspect the valve to rocker arm clearance with a feeler gauge after the first 10 hours of operation and then every 25 hours of operation thereafter.
•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 muffler cover by pressing down on it, separating it from the engine cover. Using a flat blade screwdriver, disengage the middle and front tabs and slots first. The cover will hinge off from the rear tab (Fig. 35).
2.Remove the two (2) screws on top of the engine cover with a
3.Remove the screw behind the engine cover (Fig. 37).
4.Disconnect the spark plug wire.
5.Clean dirt from around the spark plug. Remove the spark plug from the cylinder head by turning a 5/8 in. socket counterclockwise.
6.Remove the engine cover (Fig. 36).
Engine Cover
Rear Slot
and Tab
Middle Tab
| Front Tab |
Middle Slot | Front Slot |
Fig. 35
Top View Of The Engine
Remove Screws
Engine Cover
Muffler
Fig. 36
7.Clean dirt from around the rocker arm cover. Remove the screw holding the rocker arm cover with a large flat blade screwdriver or Torx
8.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 | Screw | |
travel while looking in the | ||
| ||
spark plug hole (Fig. 38) |
| |
• Both rocker arms move freely, |
| |
and both valves are closed |
|
If these statements are not true, repeat this step.
9. Slide the feeler gauge between the rocker arm and the valve return spring. Measure the clearance between the valve stem and rocker arm (Fig. 39). Measure both
the intake and exhaust valves. | Fig. 37 |
The recommended clearance for |
|
the intake and exhaust is .003 – | Rocker |
.006 in. (.076 – 0.152 mm). Use a | Arm |
standard automotive feeler gauge at | Cover |
.005 (0.127mm). The feeler gauge |
|
should slide between the rocker arm | Spark |
and valve stem with a slight amount | Plug |
of resistance, without binding. Figure | Hole |
40 shows how to measure the clearance.
Fig. 38
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