I'd agree with Jamies assessment � take all the spares you want, I'll guarantee it'll be something else that fails. My biggest issue to date has been the waterpump at 16,000 starting to weep coolant. Probably would have been OK for several more thousand miles if I kept topping up the coolant, but it was a warranty part so in to the dealer it went. The water expansion tank sprang a leak at the 12,000 service when a clumsy mix up of the fastening bolts saw the mechanic put a long one in the rear-most hole ripping the threaded insert out and causing a split in the plastic � that's just careless. Punctures don't really count as they're not failures so much as plain misfortune. Cush drives are the real weakness for a bike like this � why Yamaha are unable to make a set that will go a decent distance is quite beyond me, but then if you pack 'em they give thousands more miles of service.

All in all the Z has been the most reliable bike I've owned thus far.