The FZR600 appeared in 1988 as an upgrade from the current aircooled FZ600. It was yamaha's answer to the CBR600 which had been the top 600 for a couple of years both on road and track. The FZR's engine was based heavily on the FZ750 and FZR1000 genesis motors but only had 16valves compared to 20 due to the smaller motors inability to flow gas at lower revs. The 600 still had barrels that were canted forward to lower the bikes centre of gravity and a set of downdraught carbs just like the others. The frame was a steel version of the Japanese home market FZR400 which was a smaller version of the 1000's deltabox concept with thick beams that ran from the headstock staright to the swingarm pivot for greater frame rigidity. As well as sharing the 400's dimensions the engine shared the same bottom end and was basicly a cheaper big bored version for the UK market.
Suspension was cheap and nasty with barely any adjustment (you could adjust rear preload) but the monoshock and 38mm forks (thick for the time) still allowed the FZR to run rings around the other 600's in corners due to it's then revolutionary design which used what we now call mass centralisation. The fuel tank is almost under the seat and the tank you see is a dummy that covers the airbox.
The FZR also had the best stoppers in it's class with semi-floating discs and opposed 2 pot calipers which were upgraded in 1990 to 4 pots. They came with a 17 inch front wheel and an 18inch rear which was still the norm at the time. This causes problems now as decent modern tyres are expensive and hard to come by although some have been upgraded to 17's.
Power wise the CBR's were still on top both in terms of peak power and mid range punch. The FZR motor is useable at low and medium revs but has to be used hard to keep up with the CBR. A good one should still touch 140mph and as long as it doesn't smoke too much the motor should be fine. Gearboxes are a weak point, the bearings often fail at around 20000miles if used hard. Ride at about 30mph in 4th gear and listen for any strange rubblings and feel for any vibes through the footpegs. They get louder the worst they are.
Clutches often slip when cold, but this often clears up when the engines warm so nothing to worry about as long as it clears up. Expect to replace plates every 5000miles or so.
The FZR600 was the last true performance 600 yamaha did before the R6, both the FZR600R and Thundercat were heavier, bigger and less nimble although they were better equiped and faster. The FZR600R had a shorter stroke motor and even less mid range and bottom end as well.
As a used buy they are all a bit of a gamble, but 500 pounds could get a nice one with under 30000miles on the clock, a years mot and nothing major wrong with it. With uprated fork springs and a decent shock they can still spring surprises on a track day so for this money they are a bargain. If it does go wrong or you crash spares are literally as cheap as chips. Definatly a better way onto the road or track than an overpriced, underpowered 400.