Kawasaki Z750E Road Test
So not surprisingly, the factory's late entry into the 750cc sports arena, even tougher now since the entry of Suzuki's sixteen-valve four alongside Honda's similar offering, meets the opposition head on.
But Kawasaki hasn’t take taken the same all-guns-blazing super-high-technology approach as either of the other two factories. Instead they've made their new Z750E four relatively light and simple. Basically the bike is a bored out Z650 with a slightly modified frame. So the new seven-fifty weighs about the same as the six-fifty, 462 1bs dry making it 461b lighter than Suzuki's GSX750 and a whacking 581b lighter than the Honda CB750. That gives the Kawasaki a significant advantage in handling since the bike is still very compact as well as placing it slightly ahead of the Suzuki in its power-to-weight ratio.
The Z750E's cylinder bores are 4mm larger than the Z650 at 66mm which with the same stroke of 54mm give gives a capacity of 738cc. To improve the breathing of the double overhead cylinder head, the valve sizes are increased and the angles changed to suit the larger bores while the timing of the valves is lengthened to 30/60-60/30 from the six-fifty's 22/52-60/20 giving 270 degrees of inlet and exhaust opening from 264 and 260 degrees respectively.
The result is that the Z750E is significantly more flexible and higher revving, developing its maximum power of 74 bhp at 9,000rpm from the Z650's 64 bhp at 8,500rpm. And to allow that extra power to be more effectively used the engine breathes through a quartet of 34mm constant-vacuum Keihin carburetors instead of 24mm piston-slide types.
If you think the new Kawasaki should therefore be a flyer, then you're right. When I rode the machine recently at Donington Park the acceleration was on a par with the Z1000 up to 80mph, which gives the impression that both Honda and Suzuki have got a fight on their hands — and from a bike that's just a modification from an earlier model.
Gearing has been raised slightly from the 650 by the use of a higher final drive ratio, 33/13 that gives 120mph at peak power revs. The red line is at 9,500rpm, so if the engine will rev out in top the bike should reach the claimed 126mph top speed. Internal ratios of the gearbox remain the same but we are worried about the use of a 13 tooth gearbox sprocket — it's far too small for comfortable chain life.
With all the extra power you would also expect the Z750E to be a lively handler. And on a race track it does feel that way. But Kawasaki have uprated the suspension by the use of air pressure to supplement the coil springs in the front fork and have fitted rear units with four-way adjustable damping as well as spring preload adjustment.
The spring rates are hard, as you might expect of a super sporting machine, and the ride is on the rough side. But this means that the bike doesn't squat during cornering and the bike can be leant to amazing angles without grounding. The Dunlop Gold Seal tubeless tyres give the first hint of a limit when powering hard out of a corner with slight drifting but it is perfectly predictable and the throttle control is delicate so control is better than on the 650.
What was true about the Kawasaki 750 was that it felt exciting. It may be due to the fact that there is a lot of power in a small motorcycle — a perfect recipe for fun (vis the Yamaha RD400). But it is short with a 55.9in wheelbase (helping the cornering) and the steering is taut and positive, using the same geometry as the 650.