28 - English
Carburettor
15 Carburettor
15.1 Description
The drawings accompanying this description do not cor-
respond with the carburettor on the chainsaw. They only
show the principle for the design and function.
15.2 Design
The carburettor is based on three sub-systems:
•
The metering unit, A.
•
The mixing venturi, B.
•
The pump unit, C.
The jets and the fuel’s control functions are located in
the metering unit (A). Here the correct quantity of fuel
is adjusted for the actual speed and power output. See
Figure 1.
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.
See Figure 2.
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. See Figure 3.
Fig 2
Fig 1
Fig 3
A
B
C
WARNING!
The fuel used in the chainsaw has the
following hazardous properties:
1. The fluid and its vapour are poison-
ous.
2. Can cause skin irritation.
3. Is highly inflammable.
