Suzuki Manual Katana APO55 LIQUID COOLED 99

Hello!

I am new here and I need to make my motito somers. I am starting in these issues and what better to practice that my old Katanita.
Recently I change the spark plugs and the air filter, it had never done it and it has turned out quite well. So I want to encourage her to leave her again as new. It does not mark the speed and does not break the Sirga, I think it can be something of the piece that carries in the front wheel where the Sirga is connected, but for this I would please need some explodes of the motorcycle or repair manual that can serve me.
Please, can someone help me?
As the post -title says is a Suzuki AP AY55 LIQUID COOLED and if I remember correctly it is 99.

Thank you very much