IDLE SPEED 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. 26).
NOTE: Careless adjustments can
seriously damage your unit. An
authorized service dealer should
make carburetor adjustments.
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. 26). 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.
• 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 seven (7) screws on the back of the engine cover
with a Flat-head or T-25 Torx® screwdriver (Fig. 27).
Remove
Screws
MAINTENANCE AND REPAIR INSTRUCTIONS
Air Filter Cover
Air Filter
Back Plate
Tab
Fig. 25
Idle
Adjustment
Screw
Fig. 26
Remove
Screws
Fig. 27
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. 27).
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. 28). 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. 29).
• Both rocker arms move freely, and both valves are closed.
If these statements are not true, repeat this step.
Rocker Arms
Feeler Gauge
Spark Plug Hole
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. 29). Measure both the intake and exhaust valves.
The recommended clearance for both intake and exhaust is .003 –
.006 in. (.076 – 0.152 mm). Use a standard automotive .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 29 and 30.
Adjusting Nut
.003–.006 in.
(.076–.152 mm)
Intake Valve
Stem
Rocker
Arm
Cover
Spark
Plug
Hole
Fig. 28
Adjusting Nuts
INTAKE
EXHAUST
Fig. 29
Rocker Arm
Feeler Gauge
Valve Stem
Fig. 30
13