Tank Venting; Fuel Filter - Husqvarna 333R Workshop Manual

Fuel system

Tank venting

Check that the tank venting valve works
correctly.
Replace the fuel cap if the valve is
faulty.
531 03 06-23

Fuel filter

The fuel filter can be removed through
the tank's fill hole.
502 50 83-01
Clean the filter externally if it is not too
dirty.
Replace the filter if required.
Tank venting
Tank venting takes place through the
fuel cap and needs to be functional for
the engine to work.
• Remove the air filter cowling and
dismantle the cylinder cover.
• Remove the fuel hose from the
carburettor and empty the fuel from
the tank.
• Connect the fuel hose to pressure
tester no. 531 03 06-23.
• Pump up a pressure and vacuum of
50 kPa (0.5 bar) in the tank.
• The pressure should drop to 20 kPa
(0.2 bar) or revert to atmospheric
pressure within 45 seconds.
The fuel cap can be taken apart for
cleaning.
Use a screwdriver and press off the
housing (A) that contains a rubber
diaphragm (B) and a filter (C) and cover
(D).
Blow the filter (C) clean, and the
sintered filter (E), with compressed air
and mount the fuel cap in the reverse
order to how it was disassembled.
Make sure that the flat surface on the
cover (D) is turned towards the
diaphragm.
NOTE!
There is a small slit (F) in the
diaphragm (B) that becomes
visible when you carefully pull the
edges of the diaphragm. Check
that the edges of the slit are not
damaged. Replace diaphragm if
necessary.
Fuel filter
The fuel hose in the tank contains a fuel
filter. It is accessible through the fill
hole. Pull out the filter with your fingers
or with help of tool 502 50 83-01.
If the filter is not too dirty, its surface
can be cleaned with a brush.
Otherwise it must be replaced.
Check the fuel hose for cracks and
leaks.
Make sure that the filter's connection
neck is inserted as far as possible into
the fuel hose and that the O-ring is
sufficiently tight so that the filter cannot
slide off the tube.
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