Spark Plug; Cutting Means Maintenance; Sharpening The Line Cutting Knife; Minimum Speed Tuning - ST BC 25 H Manual De Instrucciones

Type Il
1. Remove the screw (Fig. 23.D) remove
the cover (Fig. 23.A) and then the
filtering element (Fig. 23.C);
2. Wash the filtering element (Fig.
23.C) with soap and water. Do not
use petrol or other solvents.
3. Leave the filter to dry in the open air.
4. Replace the filtering element (Fig.
23.C) and the cover (Fig. 23.B), by
tightening the screws (Fig. 23.D)

8.3 SPARK PLUG

To remove and clean the spark plug:
1. Loosen the screw (Fig. 24.A) and
remove the cover (Fig. 24.B).
2. Disconnect the cap (Fig. 24.C)
and remove the spark plug.
3. Clean the spark plug using a metal brush
to get rid of any deposits (Fig. 24.D)
Check and reset the correct distance
between the electrodes (Fig. 24.E)
4. Replace the spark plug and fasten
it firmly using the supplied wrench,
and replace the cover (Fig. 24.B),
tightening the screws (Fig. 24.A).
The spark plug must be replaced with one
with the same characteristics whenever the
electrodes have burnt or the insulation has worn.

8.4 CUTTING MEANS MAINTENANCE

When servicing the cutting means, bear in
mind that, even though the spark plug cable is
disconnected, the cutting means can still move.
Cutting means displaying the code
indicated on the Technical Data table
should be used on this machine.
Given product evolution, the cutting means
mentioned in the "Technical Data" table may
be replaced in time with others having similar
interchangeable and operating safety features.
Do not touch the cutting means until the
spark plug cable has been disconnected and
the cutting means is completely stationary.
Wear protective gloves.
8.4.1 Blade sharpening/balancing
For safety reasons, sharpening
and balancing should be done by an
Authorised Centre with suitable skills
and equipment for the job; without
risking any damage to the blade which
would make it unsafe when used.
3-point blades can be used on both sides.
When one side of the points is worn, the blade
can be turned and the other side used.
When both sides of the points are
worn, have them sharpened.
8.4.2 Blade replacement
The blade must never be repaired,
but must be replaced as soon as
signs of breaking are noted or the
sharpening limit is exceeded.
For replacement procedures, see
chap. 4.5.3 chap. 4.5.4.
8.4.3 Replacing the cutting line head
Follow the sequence indicated in (Fig. 25).
8.5 SHARPENING THE LINE
CUTTING KNIFE
1. Remove the line cutting knife (Fig.
26.A) from the guard (Fig. 26.B), by
loosening the screws (Fig. 26.C).
2. Remove the line cutting knife (Fig. 26.A) in
a vice and sharpen it using a flat file, being
careful to retain the original cutting angle.
3. Refit the line cutting knife (Fig.
26.A) on the guard (Fig. 26.B).

8.6 MINIMUM SPEED TUNING

If the cutting means moves when the
engine is running idle, contact your dealer
to have the engine adjusted correctly.

8.7 CARBURETTOR

The carburettor is tuned by the manufacturer
to achieve maximum performance in all
situations, with a minimum emission of toxic gas
in compliance with the regulations in force.
In the event of poor performance, contact your
Dealer for a check of the carburation and engine.
EN - 14