Clean Rotors for Better Brakes
I've got an 09 V with around 11,000 miles on it. Brakes have always been plenty good enough for my riding, but had started to degrade over the past six months or so - just didn't feel as strong. Didn't feel exactly like air in the line, but the brakes weren't firm. There have been lots of threads talking about improving brakes with stainless lines and other pads, so I stopped at a local Kawasaki dealer to discuss their thoughts.
One of their mechanics checked the bike, confirmed it unlikely that air was in the lines, then suggested he just check if the rotors were clean. The rotors looked clean, but he got some clean "white" shop rags, sprayed brake cleaner on the rags, and wiped both sides of each rotor with the cleaner-soaked rag. I was amazed at how much "black" came off onto the rag. Some combination of road-sludge and axle grease residue had really dirtied up the rotors - and it wasn't easy to see by just looking at the shiny rotors.
So, he cleaned the rotors a bit and suggested I take the bike home and do some more - since the brake pads also had to be dirty. Bottom line, after cleaning and re-cleaning the rotors several times, the brakes are much better.
I now check the rotors every few hundred miles, by spraying brake cleaner on a white rag and wiping the rotors. If I get any black residue, then I clean thoroughly. Made a nice difference in stopping power on my bike.
I searched and didn't find anyone else who'd had this experience, so I thought I'd just pass it on.