Idle Adjustment Screw
Fig. 50

MAINTENANCE AND REPAIR INSTRUCTIONS

Air Filter Cover

Air Filter

Tab

Fig. 49

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. 50).

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

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 in between the Air Filter Cover and the Engine Cover (Fig. 50). 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.

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), to reduce idle speed.

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 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.

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 Flat-head or T-25 Torx screwdriver (Fig. 51).

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.

4.Remove the engine cover (Fig. 51).

View Of The Rear Engine Cover

Remove

Remove

Screws

Screws

Fig. 51

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. 52). Remove the rocker arm cover and gasket.

6.Pull the starter rope slowly to

bring the piston to the top of its

Rocker

Arm

travel, (known as top dead

Cover

center). Check that:

 

• The piston is at the top of its

 

travel while looking in the

Spark

spark plug hole (Fig. 53)

Plug

• Both rocker arms move

Hole

freely, and both valves are

 

closed

 

Fig. 52

14