You 2 suspension set up's one for solo riding and one for you and the good lady.
To stop your tank slappers or bar wobbles do the following;
1/ Decrease front rebound , the slot in the middle on the top of your forks ( anti clockwise about 3-4 clicks or half a turn out)
2/Increase the rear rebound ( normally on the bottom of a shock slotted for your screwdriver take it clockwise=harder in about 2-3 turns)
3/ Rear compression on the top of your rear shock(if you have that on it- turn it in/clockwise about 1/2 turn 3 clicks)
4/ Lower the front ( drop the forks through about 2mm at a time max of 4mm) or raise the rear a few m.
Tyre pressures as already said make sure you have them at 36-42.
Bar weights will make the bars buzzy and give numb hands without , but won't make your bike tank slap.
I just read its a FZ1 n , I had one in 2006 and was the first guy in the uk to strip the airbox out and mod the fuelling and injection system to make it better and less snatchy.
The stock shock never gave me any tank slappers as I has set up the sag for me at 35mm for fast road and it worked, but the rear shock I binned as it was pathetic aftermarket or get it revalved and re-freshed imho. ( I do a lot of this foc for mates)
Cheapest things to try is tyre pressures and then get it set up for you.
Any advice on set up you need let me know and i will get back to you when I can .
Safe riding.
