Husqvarna 339XP Chainsaw User Manual


 
English 29
CARBURETTOR
Description
WARNING!
The fuel used in the chain saw has the follow-
ing hazardous properties:
The fluid and its vapour are poisonous.
Can cause skin irritation.
Is highly inflammable.
The drawings accompanying this description do not correspond
with the carburettor on the chain saw. They show purely the
principle for the design and function. The carburettor is based
on three sub-systems:
Metering unit
The needles and the fuels control functions are located in the
metering unit (A). Here the correct quantity of fuel is adjusted
for the actual speed and power output.
A
B
C
Pump unit
In the pump unit (C), fuel is pumped from the fuel tank to the
metering unit. One side of the pump diaphragm is connected to
the crankcase and pulses in time with the pressure changes in
the crankcase. The other side of the diaphragm pumps the fuel.
Mixing venturi
The mixing venturi (B) houses the choke, throttle valve and
diffuser jets. Here air is mixed with the fuel to give a fuel/air
mixture that can be ignited by the ignition spark.