Maintenance; Carburettor Adjustment - Zenoah GZ4350 Manuel D'utilisation

Introduction
WARNING: Read and understand the safety
chapter before you carry out any
maintenance work on the product.
WARNING: The start/stop switch
automatically returns to run position. In order
to prevent unintentional starting, the spark
plug cap must be removed from the spark
plug when assembling, checking and/or
performing maintenance.
WARNING: Always wear approved
protective gloves and protective goggles or
a visor.
Note: The user must only carry out the maintenance and
service work described in this Operator's Manual. More
extensive work must be carried out by a servicing
dealer.

Carburettor adjustment

Due to existing environmental and emissions legislation
your chain saw is equipped with movement limiters on
the carburetor adjuster screws. These limit the
adjustment possibilities to a maximum of a 1/2 turn.
Your Zenoah product has been designed and
manufactured to specifications that reduce harmful
exhaust fumes.
Function
• The carburetor governs the speed of the engine via
the throttle trigger. Air and fuel are mixed in the
carburetor. The air/fuel mixture is adjustable. Correct
adjustment is essential to get the best performance
from the product.
• The setting of the carburetor means that the engine
is adapted to local conditions, for example the
climate, altitude, fuel and the type of 2-stroke oil.
320 - 005 - 27.09.2017

Maintenance

1/2 1/2
• The carburetor has three adjustment controls: L (low
jet speed), H (high jet speed) and T (idle adjustment
screw).
• The L- and H-jets are used to adjust the supply of
fuel to match the rate that air is admitted, which is
controlled with the throttle. If they are screwed
clockwise the air/fuel ratio becomes leaner (less fuel)
and if they are turned anti-clockwise the ratio
becomes richer (more fuel). A lean mixture gives a
higher engine speed and a rich mixture gives a lower
engine speed.
• The T-screw regulates the throttle setting at idle
speed. If the T-screw is turned clockwise this gives a
higher idle speed; turning it anti-clockwise gives a
lower idle speed.
Basic settings and running in
The basic carburetor settings are adjusted during testing
at the factory.
CAUTION: Avoid running at a too high
speed during the first 10 hours.
CAUTION: If the saw chain rotates while it
idles the T-screw must be turned anti-
clockwise until the saw chain stops.
Recommended idle speed: 2700rpm
To adjust the carburetor
When the product has been "run-in" the carburetor
should be finely adjusted. The fine adjustment should be
carried out by a qualified person.
Note: Fine tuning may be required if the chainsaw, after
changing the type of fuel, performs differently during
start, acceleration, maximum speed etcetera.
T
H
L
25