XJ model confusion

I am confused as to what my bike actually is some say it's a seca but am finding a lot of the seca parts are not the same some say it's maxima same again with parts I have bought parts from XJ 600 that fit and parts from XJ 750 and they are the right parts and fit then some parts from xs look like they fit so I am confused as well as parts people when I talk to them what's going on my bike is an XJ 650 Yamaha 1980

 

Show us a pic
I think you’ll get a few educated guesses on here

 

Pics will help... A Yamaha dealer (and possibly others here) can look up your VIN and tell you exactly what model its supposed to be.

These bikes are old and there is a lot of individual component cross over from the various models and years.. Seca and Maxim were mostly styling packages and *most* of the time the engines of a equal size and year are mostly entirely the same.. Hogfiddles will correct me, I'm sure.

There is a very good chance that it's one model or another, and over the years mis-matched parts were swapped in because they fit, and not necessarily because they were true to the original model/year of the bike.