Husqvarna 323P4 - Manual (Page 26)

26 – English
MAINTENANCE
Oiling the air filter
Always use HUSQVARNA filter oil, art. no. 531 00 92-48. The
filter oil contains a solvent to make it spread evenly through
the filter. You should therefore avoid skin contact.
Put the filter in a plastic bag and pour the filter oil over it.
Knead the plastic bag to distribute the oil. Squeeze the
excess oil out of the filter inside the plastic bag and pour off
the excess before fitting the filter to the machine. Never use
common engine oil. This would drain through the filter quite
quickly and collect in the bottom.