18
B
Carburetor adjustment is necessary for optimum engine
performance, for safer and more economical operation. The
engine should be warm, the air
Þ
lter clean, and the chain
properly tensioned. Have carburetor adjustment done by
an authorised MAKITA service centre.
The carburetor is factory-adjusted for the air pressure at sea
level. At other elevations or under other conditions of weather,
temperature, or humidity, or when breaking in a new engine, it may
be necessary to make slight adjustments to the carburetor.
You will need a tachometer
(
9
, part No. 950 233 210)
for
optimum adjustment.
Do not go below the speci
Þ
ed setting of the main nozzle
(H). Doing so may cause engine damage due to overheating
and insuf
Þ
cient lubrication!
Use the supplied carburetor screwdriver (
8
) for carburetor adjust-
ment. It has a moulded-on projection that aids in adjusting.
Before undertaking the adjustment, run the engine for 3-5 min-
utes to warm it up, but not at high speed!
For proper adjustment, proceed as follows:
1.
Basic setting (engine off)
Start engine and warm up.
2.
Set idle
3.
Check acceleration
4.
Check top speed
5.
Check idle speed
Repeat steps 2-5 until you get the right idle speed, good
acceleration and maximum permissible
1. Basic setting
Carefully turn the adjusting screws for the main nozzle (
H
)
and idle nozzle (
L
) clockwise until you feel a stop.
Turn adjusting screws (
H
) and (
L
)
1
turn counter-clock-
wise.
2. Set idle
Set the idle speed per the technical speci
Þ
cations.
Turning the adjusting screw (
S
) in (clockwise) increases the
idle speed. Turning it out (counter-clockwise) lowers the idle
speed. In no case should the chain move.
3. Check acceleration
When the throttle is pressed, the engine should go smoothly
from idle to high speed. If this is too slow, turn the adjusting
screw (
L
) in small (max.
1
/
8
turns) increments counter-
clockwise.
4. Check top speed
The basic setting
H
=
1
and
L
=
1
gives a maximum speed of
about 13,000 rpm. For higher speed (electronically limited
to 13,500 rpm), turn the adjusting screw (
H
) a
maximum
1/4 turn clockwise.The top speed in the governor can be
clearly heard from the ignition misses.
Note:
Since there
is an electronic speed governor (limiter) at 13,500 rpm that
cuts off the ignition current, the top speed cannot be read
from the tachometer.
Important: To prevent engine dam-
age, never go below setting (H) 3/4 turns.
5. Check idle speed
Check the idle speed after setting the top speed (the chain
must not move).
Repeat the adjustment procedure starting at Step 2, until the
engine runs with the correct idle speed, good acceleration,
and top speed.
Adjusting the carburetor
(only for not EU-countries)
L
H
S
8
9
