Had me wondering if there already is a vid of someone resetting FSS on youtube. I did find a couple for the 210 chassis, which is similar. Only difference that I can think of is the "reset" button I don't think has a "zero" on it, but it is the button you use to reset the tripmeter. I think it's on the right side of the instrument panel on a 140, but not 100% on that. Just remember the tripmeter reset button. Here is the vid I found, in case you've never seen a reset done at all:
http://www.youtube.com/watch?v=QJzV0oXlUFE