Extraordinary Maintenance - Stiga SHT 660 K Operator's Manual

Replace the filter element (3) and the cover (2)
and tighten the knob (1).
4.4 CHECKING THE SPARK PLUG
Periodically remove and clean the spark plug
using a metal brush to get rid of any deposits
(Fig. 9).
Check and reset the correct distance between
the electrodes (Fig. 9).
Replace the spark plug and fasten it firmly using
the supplied wrench.
The spark plug must be replaced with one with
the same characteristics whenever the elec-
trodes have burnt or the insulation has worn, and
in any case every 100 working hours.
4.5 LUBRICATING THE REDUCTION GEAR
(Fig. 10)
Every 20 working hours, top up the level with
special molybdenum bisulphur lubrication, in-
jecting it into the lubricator (1).
4.6 LONG PERIODS OF DISUSE
IMPORTANT If you are not going to use the ma-
chine for a period of more than 2-3 months, we
recommend you do a few things before putting it
away. This will make it easier when you want to
use the machine again and will also prevent per-
manent damage to the engine.
Before putting the machine away:
– Empty the fuel tank.
– Start the engine and run it idle until it comes to
a halt, so that it uses up all the fuel that is left
in the carburettor.
– Wait for the engine to cool down before stor-
ing the machine.
When you wish to start using the machine again,
prepare it as indicated in chapter "1. Preparing
to work.

5. EXTRAORDINARY MAINTENANCE

This work must be done exclusively by your
Dealer.
All and any operations performed in unauthor-
ised centres or by unqualified persons will totally
invalidate the warranty.
5.1 TUNING MINIMUM SPEED
WARNING!
when the engine is running idle, contact your
Dealer to correctly regulate the engine.
5.2 FUEL FILTER
Inside the fuel tank there is a filter which pre-
vents impurities from entering the engine.
The filter should be replaced once a year by your
Dealer.
5.3 CARBURETTOR ADJUSTMENTS
The carburettor is tuned by the manufacturer to
achieve maximum performance in all situations,
with a minimum emission of toxic gas in compli-
ance with the regulations in force.
In the case of poor performance, first check that
the blades are not partially blocked or deformed,
on the contrary ask your Dealer to check the car-
burettor and the engine.
5.4 BLADE MAINTENANCE
WARNING!
blades are not bent or deformed and that the
screws are adequately tightened.
5.4.1 Adjusting the blades
The blades are subject to progressive wear,
which is noticed by a decrease in the trimming
performance due to excessive play of the unit.
WARNING!
eration that can damage the blades and ma-
chine or cause injuries or accidents if not
done properly. For these reasons, it must al-
ways be done by your Dealer.
5.4.2 Sharpening the blades
It is necessary to sharpen the blades when
the trimming performance decreases and the
branches tend to stick together.
WARNING!
pair a blade which has blunt cutting edges.
IMPORTANT We recommend you take your ma-
chine to your Dealer for sharpening as he has the
required tools and suitable experience.
12
If the cutting device moves
Periodically check that the
Blade adjustment is an op-
Always replace and never re-