Cycle News - Archive Issues - 1970's

.••• • i The 903cc Kawasaki ; Z-l: ~ What's to become of the King? The Kawasaki Z-l was acclaimed as the "King Motorcycle" when it was introduced about this time last year. At that time it offered the utmost in performance without discomfort, reliability without mediocrity, image without sacrifice. The 903cc Kawasaki four is still on top of the heap, but the first challenges to its superiority have arrived or are lurking just over the horizon. The 1000cc Laverda, because of its unavailability, doesn't really count as a contender, but the 900cc BMW's are going to be something for the potential Z-I buyer to consider, despite their higher price tags. Honda's biggie (we saw pictures of the horizontally opposed four the other day) will doubtlessly command a major portion of the market, and Yamaha and Suzuki Out on the road, you can enjoy aI' that power when 1;JlISSi1lll; it's effortless. Photos by Art Friedman. There's 8 smog device in there. TlIl'Ik feeds oil to BdjlllUble pump 8t countenprocket. 12 But the problem of what the bike does to the environment is non~xistent if there isn't any fuel to put in the gas tank. The fuel shortage appears to be a more immediate and pressing problem. Bigger bikes don't always get poorer mileage, in fact, a service representative recently told us that his company's 750 gets better mileage than the smaller bikes in their street line-up. His statement is not bome out by our road tests, though. Bigger bikes generally carry around more weigh t, have larger jet sizes, and travel a t higher speeds. On the other hand, they don't take as much throttle opening to go the same speed. A bigger bike with a more mildly tuned engine can conceivably get better mileage than a smaller one because it isn't wicked up so much. Such is not usually the case however. Gas mileage is affected by several built-in factors: weight of the bike and its moving parts, the state of tune and efficiency of the engine (carb size, intake and exhaust timing, compression ratio, and head shape all effect how thoroughly fuel is used), gearing, and the amount of resistance in the drive train. A bigger bike is likely to be heavier and have more weight in the drive train. But the engine is likely to be less hairy and more e fficien t. The Z·} is heavy but the engine strikes the rider as mild, and therefore, probably efficien t in terms of fuel charge use. Ours varied from 37 to 44 MPG in the more than 3000 miles that we rode it. We took two trips on it (to the San Francisco Indoor and the Phoenix Trans-Am, if you must know), and it always came up at not less than 39 MPG if we stayed within} 0 MPH of the speed limit most of the time. One of those trips was made with a passenger, too. In any event, the Z-I gets good gas mileage - about three times what you'd get in an American car. The tank will get you over 130 miles before it is time to switch to reserve which will let you drive for another 30 miles if your petcock is like ours was. What it means is that a big bike can get realistic gas mileage figures when that becomes crucial. Z-I owners say they get up to 55 MPG. That we used the bike for touring Continued on page 14 w. WOl'lI out 8 tire this W8y ••• The pipes lit out of the wey for Nrd cornering. are almost ready to release their Wankels. The over-750 class will take off in 1974. The increased activity in the bigger bike class, however, is about to be affected in eamest by the environmental crises. Wi thin a few years all motorcycles are going to have to meet certain emission standards. The Kawasaki 903 was' one of the first bikes to make any concession to cleaner air with its crankcase rebreathing system that sends oil vapors back in to the engine. Emission of hydrocarbons is reduced significantly. The Kawasaki 903 appears to be the cleanest basic motorcycle in terms of what it does to the air' of any of the New Superbikes except the lighter, simpler BMW. But itwu fun_

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