Kawasaki

KAWASAKI

NEW FOR '91

FROM THE WORLD OF RACING, TWO NEW ZX-7s

SUCCESSFUL MOTORCYCLES shouldn't be treated so shabbily. But Kawasaki's ZX-7. the basis for the Muzzy/Chandler Superbike champ and picked by this magazine the last two years as the best 750cc repliracer, has been scrapped for 1991, to be replaced with not one, but two, new Kawasakis, the ZXR750 and the limited-edition ZXR750R. Neither model shares much more than country of origin with the old ZX-7.

Why two versions of the bike? It’s no secret that Kawasaki is getting back into the roadrace game in a big way, and wants to back up its AMA Superbike championship with other titles. When Kawasaki decided to remake the ZX for 1991. it did so with a World Superbike crown in mind, so the ZXR750R is a competition-targeted machine, though it will be street-legal in Europe. At least 1000 of the machines will have to be for sale world-wide to meet homologation rules for World Superbike, as well as for AMA competition. Rumors are that only 100 of the machines will make it into America, and, like Yamaha’s OWOl, these may not be street licensable.

Sport riders unable to cop an Rmodel shouldn't despair, though; the standard ZXR is itself a pretty impressive piece. The two bikes receive the same basic frame, bodywork and engine, and it looks as if peak horsepower will be about the same, in the claimed 100-110 range.

The shared frame is all-new, and does away with the twin, bolt-on downtubes that wrapped beneath the old ZX-7’s engine cases. Instead, the frame uses massive side beams like a Yamaha Deltabox unit, with the engine acting as a structural part of the frame.

The differences between the two ZXRs include the use of an aluminum fuel tank and upgraded suspension on the limited model, though both will come with an upside-down Kayaba fork. Also, the R model will have a close-ratio transmission. Rumor is that both bikes will come with ultra-wide. 6-inch rear rims.

The new 750 engine is quite similar in design to that used in the ZXR400R, and is more compact and lighter than the previous ZX-7 engine. Its cam chain is now located at the end of the crank, like Jhe old 900 Ninja and the new-for-1991 Honda CBR600, a setup that allows narrower cases than with a center-case cam chain. Also, the engine uses a shorter stroke, going from 68mm (with a 51 mm bore) to 47mm (with a 71mm bore), which gives the machine the shortest stroke of any current 750 sportbike.

Engine-wise, the biggest difference between the two new ZXRs is in carburetion, the streetbike having constant-velocity carbs while the racer gets a bank of Keihin flatslides. The R-model will be the first bike homologated for World Superbike racing to have flat-slide carburetors as standard equipment. If each of the other Japanese manufacturers retain the use of CV carbs, the Kawasaki will have an instant edge in performance. As Rob Muzzy has said, “I don’t think we could have won the Superbike championship on CVs if the rest of the field had flat-slides.” The ZXR750R. in all its race-inspired glory, will set U.S. buyers back a tidy $10,000. not really out of line—considering Honda's RC30 went for $15.000 last year—especially if the bike can back up its good looks and impressive specifications with performance. Farther down the price scale comes the standard ZXR750, which we expect to come in under $7000. Street riders will also benefit from the standard ZXR’s revised suspension rates, said to eliminate the biggest complaint about the old 750: That it had a ride as cold and unfeeling as a repo man's heart.

With better looks, better suspension and a better engine, the new ZXR series should make a lot of people—from super-tuners to Sundaymorning riders—very happy. Our guess is that not many people are going to miss the old ZX-7.