Husqvarna 570 Workshop Manual page 31

Function
The carburettor operates differently in the following modes:
• Cold start mode
• Idling mode
• Part throttle mode
• Full throttle mode
In the cold start mode (fig. 4) the choke valve (H) is fully closed. This increases the vacuum in the carburettor so that
fuel is sucked more easily from all the diffuser jets (D, E and F). The throttle valve (I) is partly open.
closed.
In the idling mode (fig. 5) the throttle valve (I and J) is closed.
Air is sucked in through an aperture in the throttle valve and a small amount of fuel is supplied through the diffuser jet (D).
In the part throttle mode (fig. 6) the throttle valve (I) is partially open. Fuel is supplied through the diffuser jets (D and E).
In full throttle mode (fig. 7) all valves are open and fuel is supplied through all diffuser jets (D, E, F and G). Extra air inlet
(J) is also fully opened.
D E
I
Fig. 4
D
I
Fig. 6
CARBURETTOR
F
E
H
I
J
Fig. 5
J
Fig. 7
A
D E F G
Extra air inlet (J) is
J
J
English – 31