Hi, I own a 1993 FZR1000 and had the same problem. I replaced thermostat, flushed and refilled radiator, checked fan and waterpump, replaced cap and the overheating still happened. I searched online for help and you wouldnt beleive the stupid suggestions that people had. I was getting so desperate, I was almost ready to fork out my hard earned cash and take it in to the dealer. Luckily, I found an article from a guy in Europe that had the same problem and it turned out to be the head gasket. I used the bars head gasket liquid glass solution (was 5 bucks at Walmart), followed the directions. Figured 5 bucks was not a lot to spend and if it didnt work, I would have taken it into the dealer. That was a week ago and so far it looks like it worked. I´ll keep my fingers crossed it continues to work :-)