use the control screw on the oil pump
it is located on the top left side of the oil pump casing to the left of the sprocket with the chain and bar off
turn it anti clockwise the check oil output
( no chain and bar on ) if still not right try the other direction
and retry if still not putting out enough oil
may need to clean tank and pickup filter
check pump driver and drum , check oil oulet line
check oil pump itself - it could be worn or air is getting in on the oil inlet side and it not drawing oil
to get these pumps out remove clutch and drum , remove pump drinver
undo 4 x screws and remove pump assy plate
here is web site for parts
http://www.partstree.com/parts/?lc=husqvarna&mn=268+%281997-01%29
go to oil pump clutch you will see parts relationship
cheers hope it helps