Normally I would say the rear shock, this would then present a clever opportunity to introduce the fact I have an Ohlins waiting for installation, but that would be boasting, you know mentioning my Ohlins, so I will not do this.
Most annoying thing, there is no Haynes manual, or even better, a Kawasaki manual to be found anywhere. What I do is use a ZXR750 manual, because it's exactly the same bike, just slightly bigger, I guarantee this is the only difference.
There is a lack of parts available, it's almost impossible to source all the bits and pieces one requires, and believe me I have conducted an exhaustive search.
Also, and this is not ZXR specific, I've found this on all my bikes, the more I fook around with it, the more problems it gives me, it's as if Mr kawasaki actually thinke he knows more than me about setting up a bike, and yes, you can argue he twatted up the rear shock, but one should remember the ZXR was not intended for our shores in the first place.
The ZXR can be a little turd at times, fussy to start, likes to rev in strange patterns, last day out I pull up to my garage and it just dies, not because it's running badly, it's huffing, fun over, and I love it for that
So my theory is this, the ZXR really has no really annoying nuances, but it may tell you a story or two about some of it's owners :smt013