Function - Husqvarna 565 Workshop Manual

14.3 Function

The carburettor operates differently in the following
modes:
• Cold start mode
• Idling mode
• Part throttle mode
• Full throttle mode
In cold start mode the choke valve (H) is completely
shut. This increases the vacuum in the carburettor and
fuel is easier to suck from all the diffuser jets (D), (E),
and (F). The throttle valve (I) is partly open. The air
throttle valve (J) is closed. See figure 4.
In idling mode, the throttle valves (I) and (J) are closed
and the choke valve (H) is open.
Air is sucked in through an aperture in the throttle valve
and a small amount of fuel is supplied through the
diffuser jet (D). See figure 5.
In part throttle mode, the throttle valve (I) is partly open
and the choke valve (H) is fully open. Fuel is supplied
through the diffuser jets (D) and (E). The air throttle
valve (J) starts to open. See figure
In the full throttle mode both valves are open and fuel
is supplied through all four diffuser jets (D, E, F and G).
The air throttle valve (J) is fully open. See figure 7.
6.
Fig 4
Fig 5
Fig 6
Fig 7
Carburettor
English - 33