1997 Yamaha Yzf600r

CYCLE WORLD TEST

1997 YAMAHA YZF600R

STREET-WISE SUPERSPORT

IT’S ALWAYS GOOD TO KNOW WHEN TO RUN WITH THE PRIZE. YAMAHA SNATCHED the AMA 600 Supersport Championship back in 1994 with its then-new YZF600R. But the following year, faced with the prospect of suffocating under a revised CBR600F3 and an all-new Kawasaki ZX-6R, both of which featured power-boosting ram-air induction, Yamaha abandoned the class and its numberone plate. So began the factory’s two-year hiatus from 600cc competition.

• But you can't bask in the shadow of yesterday's triumphs indefinitely, espe cially in a sales class as sport-intensive as 600s. Enter the 1997 YZF600R, scheduled to be in shops this September, a little later in California. With super-sexy bodywork, revised suspension, upgraded brakes and a forced-air induction system of its own, the YZF looks set to put Yamaha back in the hunt for 1997, both on the super sport start line and in dealership showrooms.

Yamaha put things in motion by extracting class-leading performance from its existing YZF's 599cc, slant-block, liquid-cooled inline Four. Bore and stroke remain the same at 62.0 x 49.6mm as does the 12.0:1 compression ratio. Lighter, forged-aluminum pistons replace cast slugs and run in a lightened cylinder block. Adding to this is a new lightweight Ignition rotor, further reducing the motor’s reciprocating mass for improved throttle response.

Supersport racing rules allow engine tuners little latitude beyond carburetor jetting, cam timing and use of a freeflowing racing exhaust system. Previous YZFs drew air from an inlet located atop the airbox and partially smothered under the fuel tank. This presented a performance hurdle-ingesting air heated by the engine is not very conducive to peak performance. The YZF’s new intake system offers the benefits of both cooler air and a slight rise in airbox pressure at higher speeds.

With more air being piped in, a bank of 36mm Keihin carburetors has replaced the 34mm mixers of old. These new carburetors feature a water-heating system to ensure optimum performance in colder climates (engine coolant is routed to the carb bodies) and use a throttle-position sensor to determine optimum spark lead. More air in also equates to more air out. Hence, an all-new 4-2-1 exhaust system developed to improve midrange delivery via redesigned muffler internals and joint pipes pairing headers 1 and 2, and 3 and 4 midway down their length. Other features include a change in clutch-plate material along with increased clutch-spring pressure, a larger capacity liquid-cooled oil cooler and a lightweight external fuel pump.

Dyno results indicate a 3to 6-horsepower increase throughout much of the rev range, peaking at 87 bhp at 11,500 rpm. Likewise, torque output-45 foot-pounds at 9500 rpm-is up at any given point on the power curve, yielding an improvement in top-gear roll-on performance and in-town ridability. For comparative purposes, the most recent CBR600F3 we’ve tested produced 86 horsepower and 42 foot-pounds of torque, while the ZX-6R yielded figures of 90 and 44.

A convenient bar-mounted choke lever has been adopted, though during our early-summer testing the warm-blooded YZF motor seldom required its use. The slightest engine stutter is evident at cracked-throttle, low-rpm, steady-state running, but carburation is crisp throughout the rest of the rev range. Power builds smoothly with appreciable gains at 5500 and 8000 rpm. The engine feels appliance-smooth down low. There is a minor, fine-pitched vibration through the bars, pegs and tank building in intensity with revs, but it never reaches a point of annoyance.

Whether short-shifting or rowing hard through the gears under heavy load, the YZF’s six-speed box operates buttery smooth. Snap the throttle open in low gear while in the meat of the midrange, and the YZF responds with a big wheelstand. Snick a quick gear change and you’ve covered the length of a football field on the rear wheel with greater ease than most any 600. Dragstrip launches still don’t come easy aboard the YZF, though. As in the past, high-rpm starts cause clutch chatter and grabby action. Still, the new YZF posted an 11.33-second pass with a terminal speed of nearly 121 mph, easily surpassing its predecessor’s best run of 11.52 seconds at 118 mph. Yamaha has gained considerable ground on the 11.21-second/123-mph showing of the Honda F3 we last evaluated, while posting almost identical numbers to the 11.37-second/122-mph Kawasaki ZX-6R tested in that same April, 1995, issue. Considering the YZF is the portliest middleweight, weighing in at 453 pounds with a dry fuel tank-some 12 pounds more than its predecessor-the improved acceleration is a testimony to the bike’s increased power output and improved aerodynamics.

Newly shaped bodywork is claimed to have significantly lowered the 600’s coefficient of drag. With a 150-mph blast past our radar gun, the YZF enters the realm of the class’ reigning speed merchant, the ZX-6R. Until a same-day comparison under similar conditions is arranged, the Kawasaki retains the honors, though, if only by a few mph.

Outright performance isn’t the only area in which the new Yamaha makes a bid for best-in-class. Previous YZF and FZR600s were bestowed with a bare-bones track-bred appearance. The latest YZF’s fit and finish is a step above, particularly its dressed-up cockpit. Underseat storage is nicely handled with a molded compartment that includes provisions for a U-type lock. In a sport-touring role, the wellpadded, single-piece saddle, comfortable knee reliefs in the reshaped fuel tank, placement of the bars atop the upper triple-clamp and the inclusion of passenger grabrails all give the YZF excellent long-range capacity. Another big plus: The newly shaped windscreen sets a class standard in both wind protection and minimized buffeting.

Chassis geometry, along with tire and wheel size, is unchanged. Up front, weight has been pared from the fully adjustable fork, and both ends are now

sprung more softly in favor of real-world comfort over outright track performance. A broad range of damping adjustment, both front and rear, allows quick roadside calibration to suit any radical change of surface or riding intensity. Street handling remained light and neutral, with the chassis delivering a faultless, sure-footed feel when pushed to sensible limits on public roads.

No doubt the suspension compliance makes for a great daily mount, but could it work as well on the track? Preparation for a day of testing at Willow Springs Raceway called for a change of tires. While the Bridgestone Battlax BT50 radiais that come fitted from the factory perform admirably on the street, exploring the outer limits of the YZF’s handling envelope requires race-proven rubber. A set of Bridgestone BT58s, a 160/60 in the rear and a 120/70 up front, provided the level of grip we were after.

Willow’s 2.5-mile road course serves up one of the fastest sweepers in the country. When Willow’s Turn 8 is taken at race speed, you achieve peg-scratching lean angles in the neighborhood of 130 mph. The approach into this fast righthander is through a left-hand dogleg preceded by a downhill straight. A solid-handling, well-planted 600 can negotiate this section of track with the throttle pinned to the stop. But introduce a bit of chassis instability-such as a moderate wiggle that grows more pronounced through the left-to-right transition leading into Tum 8-and the throttle hand reacts accordingly. The difference between strafing Turn 8 hellbent-for-leather or adopting more of a heaven-can-wait attitude can amount to as much as a full second in lap times.

Even at an eight-tenths pace, the softly sprung YZF felt less than happy hustling into Willow’s signature sweeper. Firming up spring preload at both ends along with an appropriate increase in rebound damping did help settle the chassis somewhat, with improved feedback from the tires. But in the end, when pushed into sub 1-minute, 30-second laps, the YZF didn’t exhibit the same level of stability we’ve experienced aboard a CBR600F3 or ZX-6R running at a similar pace. The YZF’s wiggle cropped up in other areas around the nine-turn track, as well. Willow’s first comer, a medium-speed left at the end of a fast straight calls for hard braking and two downshifts, with a bit of trail braking on the tum-in. Here, the YZF protested with a lively weave carried to the comer’s apex, subsiding once power was applied and the chassis had taken a firm set.

Okay, so our laps at Willow showed that the YZF-with stock suspension rates, at least-isn’t totally comfortable in 130-mph sweepers. But they also clued us in that the YZF is biased more for fast street riding. For most riders, that’s a pretty good tradeoff. For instance, the pavement at the entrance of Turn 2 greets an already loaded front suspension. Although a slight twitch is felt through the YZF’s bars when crossing these bumps at full-scratch lean in fourth gear, its stout 41mm fork soaked it all in, keeping the tire firmly planted. Willow’s slower “Omega” section (Turns 3, 4 and 5) is a left-right-left series of second/third-gear corners. This segment of track

agreed well with the Yamaha’s nimble handling. A relaxed touch on the bars got the job done with razor-like precision.

Laps around the smaller, tighter Streets of Willow circuit offered further evidence that the stock YZF’s ultra-highspeed handling glitches will only be noticed by card-carrying roadracers. With its mix of low-gear bends, hairpins and quick flip-flop transitions, the Streets course put the YZF’s real-world agility to the test. We found riding the ragged edge at lower speeds comes quite easily aboard the YZF. In spite of the suspension plushness, cornering clearance proved better than on last year’s bike, with nothing other than the pegs and leading edge of the exhaust can touching down-and the latter only lightly grazed the tarmac a couple In the past, YZF600 front-brake pads lost their progressive feel after only minimal hard service. New one-piece four-pot calipers have given the Yamaha all the stopping power and feel we could ask for, the brakes enduring repetitive abuse with no degradation in performance. Good stuff here.of times during our fastest laps on the big track.

What’s the cost of all this goodness? At presstime, Yamaha couldn’t name a price. Early projections were in the $7500 range. We doubt if that price line can be held, but certainly the YZF will sticker less (probably way less) than the $8299 Kawasaki is asking for its ’96 ZX-6R.

So, there is no doubt that Yamaha has breathed renewed life into the YZF600R. But is this the best 600? Depends on your yardstick. If you’re a slave to the stopwatch, the answer is probably no. But if you’re looking for the best allaround 600 sportbike, a street-wise combination of backroad blaster and middleweight sport-tourer, Yamaha may just have built your next bike. □

EDITORS' NOTES

I CERTAINLY LIKE MANY THINGS ABOUT the new YZF600R. The added punch in the motor and "drop da anchor" per formance of the brakes head my list. But when I'm commuting to work or even putting in a day on my favorite backroads, what really appeals to me is the YZF's ergonomics package. Yamaha nailed it on the seat, wind screen and placement of the bars.

As a street mount, it could be the new class leader, but I need a refresher ride on a ZX-6R before tattooing such a proclamation on my butt. As for outright performance, it looks like a 600 shootout is in order, since the YZF appears to have a shot at toppling the 6R in top speed and in turning quicker laps than the CBR on the tight Streets of Willow road course.

Then again, with the prospect of a new Suzuki (ISA R600 or Honda CBR600RR lurking beyond the horizon, Yamaha's life in the limelight could be short. The shame of it is the YZF600R has been available in Europe all year. But, hey, better late than never. -

-Don Canet, Road Test Editor

A FRIEND ASKED ME A QUESTION THE other day that helped put this new YZF600 in its place. "Sportbikes sure look a lot alike," she observed. "Are they really all that different?" A naive yet valid question, because while this person isn't a very experienced rider, she also isn't much different from some 600cc sportbike buyers. -

The answer: No, sportbikes aren't all that different. More often than not, the differences are sub tle, like the shades of white paint available at Home Depot. It's up to you to pick which one suits your needs best.

How is the YZF different? Compared toHonda's CBR600F3 or Kawasaki's ZX-6R, it's clearly aimed more toward street riding than roadracing. Though the YZF's engine is no doubt strong enough to make for a competitive supersport mount, its roomy ergonomics and softly sprung suspension are better suited to spirited Sunday-morning street rides. It reminds me very much of the FZR 1000, another Yamaha that just happens to be high on my list of personal favorites. -Brian Gatterson, Executive Editor

Os~Y, HERE'S THE HOT TIP: IF YOU LIKE the new YZF600R, rocket-sled yourself down to the local Yamamart and reserve one in Vance & Hines blue. I've seen the other, duo-tone paint jobs the bike will be offered in, and the blue bike blows `em into the bulirushes. Pictures just don't do it justice-imagine an almost pearl-metallic cobalt that pos itively glows in the right light.

In many ways, that tasty paint scheme is symbolic of the whole bike. Just as it doesn't rely on splashy, ripped-edge graphics to excite, the YZF takes an intelligent approach to high performance. Go-fast supersport-racer types will jack up spring rates and replace shocks anyway; better to give street riders suspension calibrated to the sub-100-mph world most of us inhabit every day.

I'd even go so far as to call this the first real 600cc sport bike for adults, but that would make the YZF sound boring. Trust me, that's not the case.

-David Edwards, Editor-in-Chief

YAMAHA YZFGOOR

SPECIFICATIONS