Are the S40 handlebars weighted  in the ends like the LS650? And could I use bars that are not weighted. Would I get a lot of vibration ? Taanks.

I'm pretty sure my stock S40 bars were weighted, when I changed them out with buckhorn style handlebars.  No weights in the new ones and I haven't noticed any difference.

All of the stock handlebars are weighted.
And all of the bars I've used are not.
you'll probably notice more vibe's in the mirror but not bad really.
Stock mirrors are the best for mellowing out the vibes.
My taste in aftermarket mirrors tends to be cheap plastic ones which can render headlights into barn sized glowing objects.

I added a little extra steel in the ends of mine.
I think it dampened the vibes even better.

I pushed a 1" cork about 2" into one end of my drag bar, filled it with BB's, and pushed another cork to close them up tight.  Hardly any vibes at all, and cheap as well.    Less messy than foam I might add.

It takes mass to absorb vibration well.  The heavier will to better than the foam filled.

I swapped some standard Sportster bars without weights. I took some plastic cigar tubes, filled them with bird shot and epoxied the caps back on them. a couple of turns of tape made them fit without play.
The difference was noticable.