Trouble-Shooting; Cleaning And Transport Of The Machine After Use; Periods Of Inactivity; Elimination And Disposal Of The Device - Dolmar MS-4520 U Instruction Manual

6. MAINTENANCE
Flexible shaft. If you are using a backpack-type brush-
cutter, every 25 working hours grease the flexible shaft
positioned inside the sheath.
Sharpening of the grass-cutting blade. Wear on the
blade can be seen especially in the rounding of the teeth;
whenever this rounding is greater than 1 mm, re-sharpen
the blade with a few strokes of the file by keeping the
cutting edge at an angle of 30°.
Maintenance operations to be performed by a quali-
fied technician or our own Assistance Center:
Carburetor. Check the maximum and minimum carbure-
tion levels every 50 working hours.

6.3 Trouble-shooting

Whenever UNUSUAL VIBRATIONS OR NOISES are
noticed, immediately stop the engine and look for the
cause.
Whenever STARTING IS DIFFICULT (the starting cord
is hard to pull), check the following:
- defective or jammed bearings
- the piston and the cylinder might be seized
- there may be interference or contact between the drive
shaft and the case
- the starting spring may be broken or the starting cord
may be jammed.
In case of FAILED IGNITION or CHUGGING, check
the following:
- the electric system (the coil might not be providing
current, the spark-plug might be fouled, the electrode
might be broken, or the distance between electrodes
might be excessive).
- the ground button cable might be detached or bro-
ken.
- the spark-plug lug might be detached or grounded.
Whenever POWER LOSS or SUDDEN STOPPING oc-
curs in the engine, check the following:
- if there is sufficient fuel
- if the mixture reaches the carburetor (if no mixture can
be seen passing through the petrol hose)
- if the mixture filter in the tank is clogged
- if the petrol hose is clogged or crushed or de-
tached
- if the carburetor level is incorrectly set or has defects
inside (e.g. broken diaphragms), in which case the
mixture does not reach the cylinder
- that there is no water present in the mixture, in
which case the entire fuel supply system must be
cleaned
- if the tank cap breather vent is clogged
- if the carburetor's maximum jet is choked
- if the air filter is dirty or clogged
- if the ignition advance is set correctly
- if there are carbon deposits in the cylinder exhaust
pipe or the muffler.
In case of LOW QUALITY or DIFFICULT CUTTING,
check the following:
30
- cutting overload (e.g. weeds too high or thick to cut for
engine power; cutting organ tangled up in branches
or stringy vegetal matter)
- dull or worn-out blade
- worn-out clutch case or jaws
6.4 Cleaning and transport of the
machine after use
After finishing work, clean the machine and the cutting
organ from any dirt or grass, protect the blades or the
disk saws with the protection provided in order to prevent
injury during transport (Fig. 37).
Be careful to avoid damaging the tank by impact or cut-
ting, and position it carefully on the ground to prevent
falling that might cause damage.

6.5 Periods of inactivity

Whenever the brushcutter is not used for a long period
of time, adopt the following precautions:
- drain all mixture from the tank
- remove the spark-plug, inject a few drops of oil for
mixture in the cylinder, and then pull the starting cord
2-3 times to distribute the oil evenly and then replace
the spark plug
- protect the engine and all unpainted metal parts from
corrosion by providing them with a light coat of oil
- store the machine in a dry place far from dust and
accidental discovery by children
- we recommend starting the engine for a few minutes
every 60 days of inactivity.
6.6 Elimination and disposal of
the device.
Comply with the regulations in force.
Fig. 36
Fig. 37