I recently bought an 1120 that couldn't sew in reverse when I picked it up.
My DH is very handy, and he took the cover off, cleaned and oiled where needed and it sews in reverse beautifully now.
I would definitely have it looked at. I have owned a Viking, 2 Pfaffs and now a Janome 8900 and I can tell you that nothing I have had sews like that little machine.