Non Return Valve; Piston - Husqvarna 324LX Workshop Manual

Piston, crankshaft and crankcase
A
Non-return valve
The non-return valve is a leaf spring
valve that controls the oil supply to the
valve mechanism. It is located in the
bottom of the crankcase and can be
lifted out when the screws are removed.
Check the parts of the non-return valve
with regard to damage and wear, which
can cause leakage.
Make sure the leaf spring and stroke
limiter are turned the right way when
assembling.
Use Loctite on the screws when
assembled.

Piston

It is important when servicing that the
different piston rings are fitted in the
right grooves on the piston as they
have a different appearance.
Clean the piston carefully when the
new rings are fitted.
Turn the piston ring (B) so the marking
faces upwards.
The piston ring gaps should be offset
approximately 120° in relation to each
other.
Non-return valve
There is a spring leaf valve in the
bottom of the crankcase that regulates
oil discharge to the valve mechanism.
When the pressure in the crankcase
increases, the valve opens and when is
changes to an underpressure it closes.
It is therefore important that it is sealed.
Dismantle the two screws. The screws
are locked with Loctite and may be
hard to remove. If this happens, heat
the crankcase half to approximately
110°C.
Check the parts of the non-return valve
with regard to damage and wear, which
can cause leakage.
Pay particular attention to the leaf
spring (A).
Check when assembling that the cut-off
corner on the leaf spring and the stroke
limiter are positioned the right way
round.
Use Loctite on the screws when
assembled.
Piston
The piston is equipped with two
compression rings (A), (B) which have
a different appearance and an oil
scraper ring (C) consisting of three
rings (a spacer and two support rings).
Make sure the piston ring grooves are
cleaned carefully when the new piston
rings are fitted.
NOTE!
Make sure when fitting the ring
(B) that it faces the right way. The
surface that should face upwards
has a dot marked by the gap.
Turn the piston rings in their grooves so
that the piston ring gaps are offset
approximately 120° in relation to one
another.
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