Possible stupid question...I am pretty new at this

[Braden]

A friend gave me an old Aria Studiotrack IIII R504, I am not sure if it is worth much, and haven't been able to find much about it except for a thread on this very message board. But for now, refined to my bedroom, it does the trick for just recording various ideas. It records on cassettes. This is my first piece of recording gear ever, I had never bothered with it otherwise, so I am so new to this.

Anyway, my problem is the tape speed tends to slow down after a while. For instance, I will record a track, listen back to it a few times, and after awhile it seems to get slower. This is confirmed when I play over the track or try overdubbing, none of the notes match up anymore.

What can be done here?