Jelco 850 total weight

Place something that weighs a few grams on the plinth and see springs can take the extra weight!

I have both arms and while I haven't weighed them, there's not that much in it from what I can tell handling them. 
The 850 improvement in SQ is worth replacing your springs if there was a weight issue.

Yes but the springs seem to be fine for now and I would like to avoid taking it apart if I can help it.

 Part of my need to check weight stems from advice I have received that some arms are simply too heavy for the sota suspension even if it were brand new. So I just wanted to have a reality check that the 850 is not much heavier than the 750.

montaldo, aren't replacement springs available from SOTA?  Also, I read some years ago that the springs can be re-tempered by boiling in a pan, immersed in brake fluid.  You might check those solutions, then you wouldn't need to be concerned about the arm weight.