CARBURETTOR
English – 39
Basic adjustment for EPA II saws with speed limited
ignition systems and capped carburettors
The models 576XP/G and 570 are equipped with speed
limited ignition systems and capped carburettors. A slightly
different adjustment procedure is necessary when replacing
the carburettor or needles on these models.
Tachometer
Due to the integrated speed limitation in the ignition system
most tachometers will not indicate a speed above the value
that the speed limitation is set to.
Speed limitation regulates at:
570 13,300 rpm
576XP/G 13,300 rpm
Capped carburettor
This means that this chain saw is equipped with movement
limiters on the carburettor’s adjuster screws. These limit the
adjustment range to a maximum of 1/2 turn.
After replacing the carburettor or high speed and/or
low speed needle on an EPA (The US Environmental
Protection Agency) certied product, a basic adjustment
must be carried out as described below in order to
meet the EPA-requirements. This to achieve as low
emissions as possible. This instruction is made for EPA
certied products only.
On EPA carburettors both the H- and L-needles are
tted with caps to prevent the chain saw operator
from changing the adjustment above EPA standard.
The caps can be removed to achieve richer or leaner
adjustments. To set the needles correctly an adjustment
sleeve is tted from the factory over the caps to lock
them in maximum allowed settings.
When correctly set the caps must be xed on the
needles. The adjustment sleeve then can be removed.
Over the caps on complete sparepart carburettor, there
is a plastic sleeve which is intended to lock the caps
at the richest position (anticlockwise towards stop)
during the time that the needles are adjusted. When the
adjustment is complete and the caps have been xed
on the needles, the sleeve is no longer of any function
and can be removed.
Conditions
• The air lter should be clean and the cylinder cover
tted when adjustments are made. Adjusting the
carburettor with a dirty air lter will give a too lean
fuel mixture the next time the air lter is cleaned.
This can result in serious damage to the engine.
• Mount, for this model, approved bar and chain
combination (see Technical data in the Operator's
Manual).
Model
570 18"
576XP/G 20"
• The chain should not be tensioned more than that it
remains ~ 0,2 inches to the bar.
1/2
1/2
H
L
Replacement of the H-needle or complete carburettor
1. Screw the new H-needle to the bottom and turn it
counterclockwise ”A” turns.
Model
570 A = 2
576XP/G A = 3
2. Check that:
The H-cap is adjusted to its richest setting (turned
counterclockwise to stop).
The cap is not xed to the needle, it should rotate
independently.
Adjust the L-cap to a center position (1/4 turn coun
terclockwise = minimum, 1/4 turn clockwise = maximum).
3. Start the engine. If necessary, adjust the idling
speed with the T-screw until the chain stops.
4. Adjust the H-needle to give a top speed of ”B” rpm.
Use a tachometer.
Model
570 B = 13 000
576XP/G B = 13 000
Use a narrow blade screwdriver (ref.no. 531 00 48-63)
and insert it through the hole in the cap (max. blade
width 2 mm/0,08 inch).
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