At the heart of the TZR’s a water-cooled stroker parallel twin motor that peaks out at ten thou, wrapped in a well neat alloy Deltabox frame, the whole bike bearing more than a passing resemblance to Yamaha’'s track racer. To keep the road rider in line there’s crankcase reed valve induction and good old YPVS, both designed to allow maximum power at peak revs whilst not destroying the midrange.
The surprising thing about the motor is that there’s quite reasonable power below 4000rpm, when the bike takes off to 7000 revs. A point at which everything goes insane and it’s always a bit disappointing when the ignition cut-out comes in at 10000rpm. I felt there was still more power to come considering peak torque (85Nm) came in at 9750rpm, the engine could probably spin to 12 or 13 thou! However, Yamaha obviously erred on the side of caution with thoughts of engine longevity on their minds.
Now that the bike was mine I could abuse it a little. I was initially disappointed that I couldn't wheelie the Yam with ease. The only way to do a wheelie was to wind the engine up to 7000 revs and drop the clutch. Brilliant! I used to do this every day at the first set of lights after leaving work. You know the feeling, high at finishing work. Someone must’ve complained as two cop cars descended upon me as if I'd just robbed a bank. They wondered if I was really in control on just one wheel, and weren't too impressed when I gave them a lecture on the joys of the Deltabox frame. I was warned that if they saw me doing it again I was for the chop.
I plodded home at below 4000 revs, marvelling in how civilized the engine could be... there was really no need for the six gears, five would’ve been more than enough. It was no great hardship, the clutch was light and the gear change slick. About an hour’s worth of slow riding would have the engine spluttering, even with hi-tech Motul stroker oil, but all the spark plugs needed to clear the oil off them was a bit of throttle action.
An annoying aspect of the Yamaha's engine, probably a combination of the inefficiency of the reed and power valves, was that even when ridden very slowly it only turned in 40mpg, against 35mpg ridden in full throttle mode. Keeping the rev counter above 7000rpm provided tremendous kicks that resulted in the large floating front disc, with four pot caliper, being given a good work out. It was dead easy to become convinced of a God-like status, what with the body jerking acceleration and howling exhaust, stock but with some of the baffling burnt out it gave out such a glorious wail that the hair on my back stood up.
The Yam would charge up to 110mph without any discernible hesitation, then demanded that I get down on the tank to utilize the minimal nature of the screen and fairing. 120mph would come up without too much hassle but doing 125mph was rare in the extreme. By then the motor was buzzing the pegs, bars and tank; and the tyres were squirming around on suspension that suddenly felt a bit soft. Back off just a little and it's all back to supreme stability and flickability.
I found it best to turn the fork’s damping up to its maximum setting whilst keeping the single shock, operated by the well regarded mono-cross back end, on the mid settings. This gives good tautness at speed at the price of a bit of low velocity harshness. I could live with that, despite the race replica looks the riding position’s mild the seat reasonably padded (though it had been re-upholstered my mate). Only a marginal turning circle limited fast progress ugh the masses of city cagers. Several close shaves were had mad drivers who seemed astounded that a speeding projectile could appear out nowhere.
One time some git tried to do an impossible U-turn. All the lanes were jammed solid. I thought I was safe hammering down the centre of the road at 50mph. The sun caught some chrome strip on his car as he moved. I thought I wasn't going to make it, then thought I was going to be thrown over the bars hen the bike did a stoppie. I ended up an inch from the side of his car, some bug-eyed pig who gave me the V-sign before putting his foot down to continue the manoeuvre. Where the hell did he expect me to go? I back-pedalled fast as he hammered his way into the oncoming traffic. Horns, then the crunching metal. I whipped through a sudden gap and got out of there before was blamed for the six car pile-up. | think the cager had just gone completely insane after being stuck in the traffic for hours. Bikes rule!
Front disc pads lasted a mere 4000 miles, the rear’s doing about three times that. Not that the back disc brake was bad, it was very sensitive with just the right amount of power, it was just I kept getting the back wheel off the tarmac. Motorway work was dead easy. For cruising just hold her at 7000 revs, equating to just under 90mph, in sixth for as long as the fuel lasts. I started looking for a services at around 100 miles. A litre of Motul oil was needed every 600 miles, not too much of a burden and the Autolube system didn't leave too much of a smoke trail when using modern oil. Holding the bike at 7000 revs meant that all I had to do, when I needed some speed or kicks, was whack the throttle out. Instant power and acceleration. Brought a big smile to my face every time.
The other grin factor was A and B-roads. Put the Yam on a curving road and anything's possible. 17 inch wheels and Dunlop tyres help but the immense strength of the Deltabox frame and well set up suspension more than matches the crazed power that is ultimately available at the top end of the rev range. Riding a bike on the edge of its tyres was a new experience for me!
OK, I'll admit that the TZR’s a touch dated and down on power against the latest crop of 250 replicas but the Yam was so comfortable, so assured, that on long races with these chaps I invariably made up for any deficit in power by the sheer togetherness and persistence of the package. When they started stopping for a break every 25 miles I knew I was going to win out. It was quite funny watching them straighten up, massaging their backsides.
The handling turned a little crazed when either the tyres wore out (a rear lasted 4500 miles) or some component in the suspension ended its natural life. I had the mono-cross bearings, fork seals and the swinging arm bearings go on mine (between fourteen and seventeen thousand miles). The bike was OK below 30mph but incredibly sensitive at higher speeds.
Engine-wise I ended up cleaning the powervalves three times, changing the gearbox oil every 3000 miles and putting in new Spark plugs every 500 miles. They would last longer but starting became a fifth or sixth kick affair instead of first or second. Not much effort was needed but I would’ve preferred an electric boot - useful if the motor stalls in traffic. Finish was good, but then I cleaned and polished the bike every day.
With 22000 miles done the engine seems as reliable and powerful as ever. Insurance rules out buying anything more powerful but I’m pretty happy with the TZR and still have plenty of kicks.
John Lee