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Service – Dolmar PS-420 User Manual

Page 32

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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