I've been bleeding this thing at the banjo's and the screws and tying the brake lever at night with a bungee. I removed the master cylinder from handlebar to try to release any trapped air. A short test and the bike stops just fine but the travel is still nearly reaching, if not touching, the grip. (You know what just occurred to me as I typed this is that I installed larger grips on it the day I brought it home from the dealer. There's probably an additional quarter inch on the radius of the grip.) Today I try mass bombing. I'm going to run a full pint of brake fluid through the system bleeding only at the screws and then tie it off overnight. Whatever I get, I get. I'll let you know.
Sounds like you might have normal travel with old rubber brake lines. Install 'life-time' stainless hoses from Murph and you will have a rock solid feel more than stock hoses ever did.
This is replacement info from the Kawasaki Service Manual. How old are yours?
Brake hose - replace
Replace every 4 years
Master cylinder. Cup & dust seal
Replace every 2 years
Caliper piston seal & dust seal
Replace every 2 years