YAMAHA FJ1100
Chris Moss on the history of the FJ and more besides.
Yamaha may well have had great success with its two-stoke race and road bikes in the Seventies and early Eighties, but when it came to building a big capacity four-stroke sportsbike, the men from Hamamatsu lagged behind the competition. The 1977 XS750 and 1978 XS1100 had some virtues, but neither could hold a candle to their Japanese rivals when it came to outright performance. The new decade brought more promise with the commendable XJ900 in 1983, but it wasn't until the following year that Yamaha finally built a sportsbike to truly run with the pack. Enter the firm's new flagship, the FJ1100 – a genuine superbike that kicked out a heady 125bhp and tripped the timing lights at over 150mph. Yamaha had arrived with a big bang. The FJ was instantly heralded by members of the press, who were impressed by the strength of the FJ'S 1097cc inline four engine. The praise also extended to the bike's precise handling and comfort and it almost became a victim of its own success, with demand exceeding supply and the FJ quickly selling out. If you wanted one of the new Yamaha superbikes, you had to wait. Many were prepared to, and as it compared favourably in bike mag tests to the likes of Kawasaki's GPZ1100, Suzuki's Katana 1100, and Honda's VF1000, that should have been no surprise. Even when the sensational GPZ900R arrived, some journos still rated the FJ as highly as the Kwacker, others even thought it was fractionally better. At the 1984 Production TT, the FJ underlined its sporting potential with a fourth-place finish in the hands of one Mr Steve Parrish, who wasn't a million miles behind race-winner Geoff Johnson aboard one of the 900Rs. Technically, the Yamaha wasn't exactly revolutionary, though it did reflect Yamaha's desire to do things differently in some areas. Centrepiece, and warranting all the plaudits it received, was the 1097cc, air-cooled, DOHC, 16v motor. Sporting compact overall dimensions, in part due to the position of the chain driven alternator behind the cylinders, it produced a class-leading 125bhp. But it was the torque, and more to the point, the broad spread of that immense grunt that characterised the 1100. With drive produced very strongly from almost zero revs, and boosted by a potent mid-range, frantic revving and gear changing weren't necessary to deliver high speed. Top gear roll-ons were especially impressive: the pulling power necessitated just a five-speed gearbox, with suggestions from some that four ratios probably would have sufficed. If you did decide to get more serious, from a standstill you could ultimately fly through the quarter-mile at over 120mph, taking just over 11sec to get there. The bore and stroke of each cylinder measured 74 x 63.8mm, with the four pots fed by four 36mm CV Mikunis. Their mix was drawn through and emptied via 29mm inlet and 25mm exhaust valves, the clearances of which were shim-adjusted. Camshafts were hollow to save weight and driven by an inverted chain, tensioned automatically. The ignition system was clever in that its spark advance was controlled by both rpm and engine load measured by a vacuum unit in the inlet tract. The engine was cooled and protected by two oil pumps, the larger of the pair feeding the engine directly, the other pumpin l through the system's oil cooler. Crankcases
drilled internally between cylinders to reduce piston pumping losses. Less conventional was the Yamaha's 'Lateral Frame Concept'. Made from box-section steel, the frame's main spars ran up from the swingarm pivot area, passing outside the cylinder head. Beyond there, they were joined together by a cross member ahead of the headstock. Along with the forks, the steering head was more securely supported inside the main spars by three sections of small diameter steel tube. The triangulated structure was claimed to offer greater stiffness, and likened to similar designs used by Bimota at the time. The head angle was set at 27.5 degrees, with trail measuring 112mm. The box-section lower frame rails could be unbolted to allow easier engine removal, with the main spars set apart wide enough to facilitate head and cylinder removal should you want to leave the motor in place. The forks were 41mm telescopic units featuring preload, as well as combined compression and rebound damping adjustment. Hydraulic anti-dive units, linked to the twin piston front brake calipers, managed the forks' compression whenever the pads gripped the 282mm ventilated discs. Controlling the alloy box-section swingarm, a vertically mounted rising-rate 'Monocross' rear shock could also be fully adjusted. Preload changes were made by turning a remote adjuster linked to the shock via a novel short chain and sprocket arrangement. There was also a knob to alter the shock's damping remotely. Helping the FJ to sit lower were a pair of 16in six-spoke wheels fitted with crossply tyres: the front a 120/80, and the rear a massive 150/80. The Yamaha's manageability was helped by the very low 780mm
seat height, and comfort assisted further by the frame-mounted fairing and roomy, quite upright riding position. Testers enjoyed the 1100's precise and predictable handling, though some thought the bike dropped into corners too readily at slower speeds. On track it performed well with good steering, decent brakes, and impressive stability. Enthusiasm through corners was greeted by prematurely grinding footrests, followed by the centrest and and belly-pan. Real-world features such as the grab-rail, manual headlight adjuster, centrest and lifting handle, and big 24.5-litre nk boosted the FJ'S versatility and appeal. For 1986 the Yamaha got a bigger engine. With s 3mm bigger bore, capacity increased to 1188cc. Now labelled as the FJ1200, it was clear the bike's role was beginning to change slightly with more emphasis placed on fitting it into the sports tourer category. Increased competition from more focused machinery like the GSX-R750 and 1100, GPZ1000RX, and more importantly, knowledge of its own FZR1000 Genesis being readied for launch the following year, further encouraged the class shift. As well as the extra ccs, the engine tune was changed with slightly milder cams. The result was the same maximum horsepower, slightly more peak torque. More importantly, there was some extra shove in the midrange. Overall gearing was raised to take advantage of this. Cylinders were cast differently to run cooler and reduce oil consumption, the head bolted down with stronger studs, and airbox modded to reduce intake noise. The exhaust system was lighter and quieter and featured stainless steel headers. A new fairing, with its flush-fitting indicators and bolted-on mirrors, was claimed to give a smoother airflow around the rider and came with an optional taller screen. Fitted to its left-hand panel were a new fuel reserve switch and choke knob. Instruments now featured a clock. The 1200's tank capacity was reduced to 22 litres and now had a flush-fitting, aircraft-style filler cap. Twin grab handles replaced the single grab rail. Rear suspension linkages were fitted with needle roller bearings, and a longer gear-lever and redesigned shift mechanism made changes easier. The new 1200 was nine kilos heavier at a claimed 236kg. The biggest change on the second generation 1200, launched in 1988, was the bigger 17in front wheel: the rear stayed the same at 16, though both were now of a three-spoke FZR style design. Braking was improved with the fitment of larger 298mm floating discs and four-piston calipers. The fairing and headlight were redesigned, the seat reshaped, and pillion footrest became rubber-mounted. The anti-dive fork system was dropped, and ABS became an option. A fuel pump and new clocks were fitted, and the airbox now had a single air intake. The new FJ weighed in at 238kg. The final edition of the FJ1200 came in 1991 and lasted until 1995. The engine had newly positioned rubber mounts, though no longer being a stressed member ironically resulted in some minor vibration. The box-section swingarm, and lower fork yoke were now made of steel, and the 1200 was further distinguished by its new fairing and tapered headlight shape. A new shock, without the novel remote preload adjuster, was fitted and the forks only featured preload tuning. The last FJ got a new maintenance-free battery, modified oil-cooler, and re-sited pillion footrests. ABS became standard fitment in 1993, this version of the FJ weighing 248kg. Though this was distinctly weightier than the 227kg original model, the fact it didn't change too markedly during its 13-year term is a clear sign of customer satisfaction. It had been a class leader and sports tourer during its time, and has gone on to be considered a modern classic.