I bought a MT Fuji bike that is missing the rear derailleur. Part of it and the mounting bolt are still on the bike. The Derailleur apparently pivots on a shoulder on the mounting bolt. The front derailleur is a Suntour Mountech. The bike is an 18 speed. I can't find out much about the bike except it doesn't look anything like the new models.
What derailleur came on this bike and/or what economical derailleur will work on it?
Thanks
Lloyd

Is it a 1990 or a 1991, is it white ?

I don't know what year it is. It is Green. The serial number is: FK, followed by 6 numbers.
Lloyd