Yamaha FZR1000

The FZR1000 engine was developed from the Yamaha FZ750 with the same liquid-cooled 5 valve per cylinder (3 inlet and 2 exhaust) engine design with 45' inclined cylinder block. The engine bore and stroke were increased to give a new capacity of 989cc. The increase in cylinder bore permitted larger valve sizes and correspondingly larger 37mm BDB Mikuni CV carburetors. The lubrication system was enhanced with a dual rotor oil pump and external oil cooler.

In 1989 the machine received a major redesign, again the bore and stoke were changed to give a new capacity of 1002cc, the cylinder block angle was changed to 35' to reduce the wheelbase and permit a ram-air intake. The intake system was redesigned with even larger carburetors, larger intake and exhaust ports.

A unique feature that gave the new EXUP model its commonly used name was Yamaha's four-stroke power valve system EXUP valve, a servo-motor-driven exhaust valve. This allowed large bore exhaust for improved gas flow at high engine speeds but with good low engine speed performance thanks the engine speed controlled exhaust valve restricting flow at lower revs. The new EXUP machine gave class leading pulling power from low revs, seamlessly, up to the red line at 11,500 rpm. It also allowed extremely radical high lift cams that gave a very lumpy idle when unplugged in the open position or when using a full aftermarket exhaust. Yamaha continued to use the EXUP valve system on the subsequent Yamaha YZF1000R Thunderace and Yamaha YZF-R1 motorcycles.

The FZ1000 uses a five-speed sequential close ratio gearbox. The clutch is of the wet, multi-plate type and is hydraulically operated. Final drive is by O-ring chain and sprockets.

The FZR1000 chassis provided the biggest advancement over the original Yamaha FZ750. A major reduction of frame weight resulted from the use of an all aluminum ssquare section 'Deltabox' perimeter type frame. The frame consisted of cast and extruded sections, welded together and provided a large weight reduction, in region of a 40% over the equivalent steel frame.. Although first seen on Yamaha racing machines such as the FZ750 OU74 race machine [6] and in use on other smaller capacity or racing motorcycles, this was the first use on a such a large production motorcycle. Aluminum perimeter frames are now common amongst contemporary sports motorcycles. The new frame was complemented by large 41mm diameter Telescopic forks, cast aluminum hollow spoke wheels suitable for radial tyres.

FZR1000 Genesis Frame

The 1989 redesign that resulted in the 'EXUP' bikes, provided a major refinement of the Deltabox frame, the more compact engine allowed a completely redesigned and smaller frame and along with the new 17" rear wheel and 43mm Telescopic forks. The machine was thus shorter, lower, stiffer and lighter than the previous model. The bodywork was also redesigned resulting in an almost new machine.

In 1991 a further redesign resulted in the release of the FZR1000RU EXUP, upside-down telescopic forks were fitted and the front fairing was fitted with a single headlight, generally regarded to be the definitive FZR1000. By 1994 the machine reverted to twin headlights, although now 'Fox Eye' styled, braking however was improved with the fitment of six piston front brake calipers.