McCulloch MAC 250 B Instruction Manual page 15

BLADE REPLACEMENT
Refer to the ASSEMBLY section for blade re-
placement instructions and illustrations.
CARBURETOR ADJUSTMENT
WARNING:
Keep others away when
making idle speed adjustments. The trimmer
head will be spinning during most of this pro-
cedure. Wear your protective equipment and
observe all safety precautions. After making
adjustments, the trimmer head must not
move/spin at idle speed.
The carburetor has been carefully set at the
factory. Adjustments may be necessary if you
notice any of the following conditions:
S Engine will not idle when the throttle is re-
leased.
S The trimmer head moves/spins at idle speed.
Make adjustments with the unit supported so
the cutting attachment is off the ground and
will not make contact with any object. Hold the
unit by hand while running and making adjust-
ments. Keep all parts of your body away from
the cutting attachment and muffler.
Idle Speed Adjustment
Allow engine to idle. Adjust speed until engine
runs without trimmer head moving or spinning
(idle speed too fast) or engine stalling (idle
speed too slow).
WARNING:
Perform the following
steps after each use:
S Allow engine to cool before storing or trans-
porting.
S Store unit and fuel in a well ventilated area
where fuel vapors cannot reach sparks or
open flames from water heaters, electric
motors or switches, furnaces, etc.
S Empty fuel tank before storing or transport-
ing the unit.
S Store unit and fuel well out of the reach of
children.
S Store unit with all guards in place. Position
unit so that any sharp object cannot acci-
dentally cause injury.
SEASONAL STORAGE
Prepare unit for storage at end of season or if
it will not be used for 30 days or more.
If your unit is to be stored for a period of time:
S Clean the entire unit before lengthy storage.
S Store in a clean dry area.
S Lightly oil external metal surfaces.
S Turn idle speed screw clockwise to in-
crease engine speed if engine stalls or dies.
S Turn idle speed screw counterclockwise to
decrease engine speed if trimmer head
moves or spins at idle speed.
WARNING:
after each adjustment. The trimmer head
must not move or spin at idle speed to avoid
serious injury to the operator or others.
If you require further assistance or are unsure
about performing this procedure, contact an
authorised service dealer.
STORAGE
ENGINE
S Remove spark plug and pour 1 teaspoon of
40:1, 2-cycle engine oil (air cooled) through
the spark plug opening. Slowly pull the
starter rope 8 to 10 times to distribute oil.
S Replace spark plug with new one of recom-
mended type and heat range.
S Clean air filter.
S Check entire unit for loose screws, nuts,
and bolts. Replace any damaged, broken,
or worn parts.
S At the beginning of the next season, use
only fresh fuel having the proper petrol to oil
ratio.
OTHER
S Do not store petrol from one season to
another.
S Replace your petrol can if it starts to rust.
15
Recheck the idle speed
Idle Speed Screw
Air Filter Cover