The Zed’s liquid-cooled, inline four-cylinder motor is bored-out to 806cc. Bore and stroke is now 71 x 50.9mm (the old bore was 8.4mm). Power is up from the Z750’s 105bhp to 111bhp and the overall gearing is shorter thanks to a two teeth bigger rear sprocket (up from 43 to 45). These two main changes are responsible for the Kawasaki’s extra grunt out of corners and power all the way through the revs.
Revised intake and exhaust ports, longer intake ducts (up from 36.5mm to 41.5mm) and a new intake funnel arrangement, where the inner two trumpets are longer then the outers, all help boost mid-range power.
There’s a new fully-aluminium die-cast cylinder head with plated bores, which is 1kg lighter than before, 10% lighter pistons, bigger oil jets, wider radius crankshaft journals, a redesigned oil pan, a new camchain with smaller side plates and new intake valve seat material. Throttle bodies are up 2mm to 34mm.
Detail changes inside the gearbox and clutch mechanism offer more durability and an easier action.
To boost midrange, the exhaust header pipes are made as long as possible. They curve beautifully outwards before coming back underneath the engine and into a new, stubby end can.