Fuel Pump; Carburettor - Husqvarna 333R Workshop Manual

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Fuel system

Fuel pump

The fuel pump facilitates cold starts.
The pump cannot be repaired and must
be replaced if it stops working.
Note how the fuel hoses are connected
to simplify assembly.

Carburettor

Dismantling
Blow clean the carburettor
compartment and remove the screws
holding the carburettor and the air filter
housing.
Lift off the carburettor and the air filter
housing.
Disconnect the pressure rods and
remove the fuel hose.
The carburettor's design
The carburettor can be divided into
three different functional units: the
metering unit, the blending unit, and the
pump unit.
The metering unit
The needles and the fuel control
functions are located here.
Fuel pump
The fuel pump has the task of
facilitating the start of the engine when
cold. The pump fills the carburettor with
fuel before attempting to start the
engine. This also prevents vapour
bubbles from blocking the narrow fuel
channels.
If the pump does not work it must be
replaced.
Note how the fuel hoses are connected
to simplify assembly.
Carburettor
Dismantling
1.Remove the air filter cover and
cylinder cover and blow clean the
carburettor compartment using
compressed air.
2.Remove the three screws holding the
carburettor and the air filter housing.
NOTE!
Do not lose the washer under the
head of the upper screw.
3.Lift off the carburettor and the air filter
housing from the cylinder and
disconnect the throttle cable, the fuel
hose from the carburettor and pull up
the fuel hose, which joins the tank
and the fuel pump, from the tank.
Remove the remaining fuel hose (1)
and both pressure rods (2) and (3).
The carburettor's design
The carburettor can be divided into
three different functional units: the
metering unit, the blending unit, and the
pump unit.
The metering unit
The needles (A) and the fuel control
functions are located here.
The needle valve (B) and control
diaphragm (C) are vital to the
carburettor's function.