Before Starting; Engine Starting; Breaking In The Engine - Dolmar MS-4520 U Instruction Manual

4. STARTING

4.4 Before starting

Before starting the machine, make sure that it has been
carefully positioned on a fl at, clean surface free from
obstacles. Then set it up in horizontal position in such
way that the cutting tool does not touch the soil or any
other object. Make sure that all the screws, especially
the fi xing screws for the rod, safety guard, and cutting
organ are well tightened. Make sure that both the cut ting
tools and the respective safety guard have been cor-
rectly assembled as above. Whenever possible, clean
the cutting area before be gin ning to work by collecting all
foreign objects such as stones, pieces of bro ken glass,
nails, metal wire or string that might be thrown off or
become tangled up in the cutting tool.
Starting the machine inside closed rooms
or buildings is pro hib it ed, and breathing the
ex haust fumes can lead to intoxication.
Remember that the use of the head with the nylon cut-
ting wire leads to the spraying of chopped grass and
vegetal matter.
Pay special attention whenever cutting toxic
grass. Use adequate respiratory system pro-
tec tions.

4.5 Engine starting

Proceed as follows to start the engine:
1) After carefully completing all the operations re quired
for preparation and fuel supply, set the gas control
lever and the red button in the START position.
2) Grip the brushcutter with the left hand and press the
transmission rod in order to keep it fi rmly positioned
on the ground (Fig. 20), and then use the right hand
to slowly pull the starting cord until the pawls hook
on the fl ywheel.
3) Follow the instructions regarding the carburetor pro-
vid ed below and then pull the starting cord with force
until the machine starts up. Never pull the starting
cord all the way out in order to avoid damaging its
connection mechanism.
Brushcutters with piston displacements of 45 c.c. and
above are equipped with a decompressor that fa cil i tates
the starting of the engine by reducing the amount of force
to be applied to the starting cord when the machine is
being started.
In order to start these types of brushcutters, press the
decompressor button (Fig. 21) positioned on the cyl in der
at the side of the starting and then proceed as in di cat ed
in point 1.
Depending on the type of carburetor supplied with your
machine, perform the operations specifi ed below:
26
Carburetor mixture priming bulb and black starting
button (Fig. 22/A)
- with the engine cold, press the priming bulb 1 on the
carburetor 5-6 times until mixture fl ows out of the re-
spec tive discharge hose 3 (in order to completely fi ll
all the carburetor chambers).
- press the black starting button 2 once or twice. This
button serves to inject the right quantity of mixture
required for starting.
- pull the starting cord 1 - 2 times until the engine starts
fi ring. If the engine fails to start, repeat the operation
above.
Carburetor mixture priming bulb without black start-
ing button (Fig. 22/B):
- with the engine cold, press the priming bulb 1 5-6 times
until mixture fl ows out of the respective dis charge hose
3 (in order to completely fi ll all the carburetor cham-
bers).
- set the air lever (Fig. 23-24) in the CLOSE position, and
pull the starting cord from 1 - 2 times until the engine
starts fi ring. Even if no fi ring sounds are heard, return
the air lever to the OPEN position.
- pull the starting cord once again until the engine starts.
If the engine fails to start after the fourth pull, repeat
the operations above starting from point 1.
If, despite all these attempts, the engine fails to start,
the combustion chamber must be fl ooded. In this case,
unscrew, remove and dry the spark-plug and pull the
starting cord several times without the spark-plug in
po si tion in order to clean/ventilate the combustion
cham ber.
IMPORTANT: not all these operations must be per-
formed when the engine is already hot; it is suf fi cient
to merely pull the starting cord with the but ton in
the central position until the engine starts.

4.6 Breaking in the engine

For the fi rst 10 hours of operation, run the engine at
moderate rpm, or in any case, refrain from bringing the
engine to the maximum rpm until the engine's parts have
been broken in. The engine can be run at peak power
only after it has been correctly broken in.
After the fi rst 2 hours of operation, check the tightening
of all the screws and nuts, and tighten if necessary.