Dolmar PS-420 - Manual (Page 32)

2
S H L
SERVICE
Adjusting the carburetor
CAUTION: Carburetor adjustment may only be done by a
specialist DOLMAR service center!
Do not undertake any adjustments to adjusting screws (H)
and (L) without a tachometer! Incorrect adjustment can lead
to engine damage!
A tachometer is needed for adjustments to adjusting screws
(H) and (L), because if the engine runs over its maximum
rated speed, it can overheat and run out of lubricant. This
can damage the engine!
Only adjusting screw (S) can be manipulated by the user.
If the saw chain moves in idle (i.e. without the throttle being
pressed), it is imperative to correct the idle speed!
Do not adjust the idle speed until after complete assembly
and testing of the saw!
Idle speed adjustment must only be undertaken when
the engine is warm, with a clean air filter and properly in-
stalled guide bar and chain.
Use a screwdriver (5/2” (4 mm) blade) for idle adjustments.
Adjusting the idle speed
Turn adjusting screw (S) counter-clockwise (unscrew): Idle
speed decreases.
Turn adjusting screw (S) clockwise (screw in): Idle speed
increases.
Important: If the saw chain still moves during idle even
after you have adjusted the idle speed, do NOT use the
saw. Take it to a DOLMAR service center!
Note:
Carburetor adjustment aids in proper functioning, economi-
cal consumption, and safe operation.
Because of new exhaust regulations, the carburetor adjust-
ing screw (H) now comes with a limit feature. The reduced
adjustment range (about 180 degrees) prevents excessively
rich carburetor settings. On some models, the adjusting screw
(H) is locked. This ensures compliance with exhaust regula-
tions, as well as good engine functioning and economical fuel
consumption.
SERVICE