That’s an oldie! It may be malfunctioning, or it may be simply that the needle is worn out. The unit you have on hand is a 1984 / 1985 model year product. This makes it more or less 23 years old. If that’s the original needle (or even the second replacement!), I'd throw out a wild guess that a new needle would work wonders. You should be able to pick up a replacement needle for less than $30.00 or so.
Cartridges come with specifications for recommended and maximum tracking weight. The recommended is the neighborhood of where you can generally expect the best results; the maximum is that which, when you exceed it, damage starts.There are a number of other cartridge and tonearm parameters. Any of of them being off will produce poor quality playback.
is your first sample after some declicking. Does this address your complaint with the recording?