What is this rubber pad on my front brake disk? Is it needed it blocks my xena lock?

 

I don't know what it's called either, but I have one too, albeit black.

 

If I'm seeing the part correctly in the pic, I think that's a vibration/sound damper to work with the disc rotor.

 

so it is needed? cant get zena lock on with it there

 

No, it is not needed. You can remove it. If you hear a new noise it may be a bit of noise from the rotor, but no big deal. My 650 has one on the rear, 250 has none

 

I don't know if even Kawasaki knows if it really works. Some engineer had an idea, and it probably served a purpose in some testing, but it's hardly going to knock the earth off its axis if you remove it. Over the years I've seen a lot of similar devices on or around hubs and rotors on Kawasakis and other brands...only street registered bikes as I can recall...but not totally sure on that. Brake noise and other wheel associated noises and harmonics are the bane of motorcycle engineers on street bikes. They'll try anything.