While I agree with the basic tenants of what @Anarach has said in the comment, there is one possible blaring issue with the motorcycle, that being: was it broke in properly. I'm not talking about, what do people on the forums say, I'm talking about how Kawasaki says it should be broken in. In the owners manual (which you can download here), it states:
The first 1600 KM (1000 mile) that the motorcycle is ridden is designated as the break-in period. If the motorcycle is not used carefully during this period, you may very well end up with a "broken down" instead of a "broken in" motorcycle after a few thousand kilometers.
The following rules should be observed during the break-in period.
- The following is the maximum recommended engine speed during the break-in period:
Distance traveled Max engine speed
0~800 km (0~500 mile) 4000 rpm
800~1600 km (500~1000 mile) 6000 rpm
Every person who is trying to sell a motorcycle will tell you, "Oh, I followed those rules exactly." ... but how do you know for sure? There is no way to measure anything. There is no way to verify. More than likely, they have followed the rules, but you just don't know for sure. This would leave a huge gap in my mind telling me to walk away from it.
The break-in is a very important procedure. Without following it to the letter, any warranty which exists with Kawasaki will be null and void.