The magazine for classic Japanese motorcycles

Bridging the years

In the world of motorcycle development things don’t stay the same for long. Continual testing and development is the nature of the beast and the frenetic pace of racing is what drives it along. Just take a look at the Suzuki GSX-R750 as a prime example. Twenty-five years old this year, the original and most recent models of the GSX-R share nothing in common but the name (and attitude) and racing has driven it all.

One of the longest running engines was fitted to the Suzuki Bandit; it used an air/oil-cooled motor from the GSX-R1100 right up until 2007 when it was given its own water-cooled motor to help it get through tighter emissions regulations.

But one engine has been in continual use for even longer. The Yamaha FJ1100 was launched in 1984 and a derivative of its engine is still used today. When Yamaha Motor Company launched their 1984 sportbike FJ there’s no way they could have envisaged the motor would have a life of more than a few years. Yet 26 years on that engine is still powering the company’s retro flagship – the XJR1300. But let’s start at the beginning.

Bike father

The FJ1100 was launched in 1984 and billed as a sports machine with high speed touring ability. You disagree? Well, you only have to look at the original advertising literature for the bike with pictures of the speedo and rev-counter at maximum and the rider with his head buried behind the small (for the time) screen in a top-speed seeking crouch. They might have mentioned ‘tourer’ but not without a significant slant towards the high-speed side of things.

The mid-80s were a time of frenetic development in all areas of motorcycle design and, while people don’t seem to remember it now, the humble FJ was at the very cutting edge of motorcycle trends.

Firstly, there’s the Lateral Frame Concept that Yamaha proudly emblazoned on the fairing. Yamaha took note of Bimota’s frame design of the time and applied it to their new bike. Basically, the upper rails of the perimeter frame extend beyond the headstock and then meet, rather than being welded to either side of the headstock. The headstock is then braced to the sides and the front to give it support in all directions. This gives it an amazing rigidity, which is being exploited to this very day by Phil ‘Doc’ Hacker, the FJ Owners Club FJ mechanic. You see, Phil races an FJ in the Forgotten Era championship and wins. A lot. But we’ll come back to that later.

Like I said, the FJ was ahead of its time. Not only was the frame different, the bike had 16-inch wheels for quick and nimble handling and the suspension was in a class of its own. Yamaha had decided that the owners of their new flagship should be able to adjust their own suspension – something previously only toyed with by the other manufacturers. Even today the level of adjustment is well-spec’d. The front forks are adjustable for preload and anti-dive and the rear shock has damping adjustment along with a remote spring preload adjuster that is actuated by a chain and sprocket arrangement. Very neat.

Not only did the FJ have adjustable suspension but it also featured ventilated discs on both the front and rear wheels gripped by twin two-piston calipers at the front. The early FJ1200s came with ventilated discs too but they were dropped in favour of solid discs on later models.

But interesting as this is, it’s all past tense. We wanted to find out what FJs are like as an ownership proposition today. This is where Phil comes in very handy because, being an FJ mechanic and racer, he has more than a few FJs in his garage. His road bike is a mix of old, slightly less old and quite recent. A common modification is to fit wheels from the Yamaha FZR series to give access to radial rubber. Phil has done this to his bike but also explains that the original tyre sizes work well, it’s just that the more modern rubber gives different handling characteristics. Just to prove the point he brought along an early FJ1200 and his own modified bike. He’s right of course, the original bike has plenty of grip from its tyres but it steers far more quickly than the modified machine – almost nervously and it takes a while to get used to it.

The motor itself is a beauty. The 16-valve four has plenty of torque that means changing out of fifth is only needed for the fastest of overtakes. Lazy top gear riding is easy to do but keep the engine revving and it has a turn of speed that makes you realise the brochures weren’t far off the mark. This is a 150mph motorcycle after all.

As the years went by, the FJ became heavier and less fuel efficient, “the early carbs work better than the later ones – they’ve got different slides etc,” explains Phil, “It had more accessories bolted to it and it became much more of a tourer rather than a sportster.” Eventually the FJ became the FJR; a purpose built tourer with a new water-cooled engine, an electrically adjustable barn-door of a fairing and an optional semi-automatic gearbox. Or that’s the common misconception. No, the FJ1100 eventually became the XJR1300. Don’t believe me? Read on...

Bike son

When magazine reports say that an engine in their new bike is derived from another in their range, the journalists in question rarely know exactly what the exact details are. This isn’t always because they don’t have the requisite knowledge – it’s just that the manufacturers rarely provide the information. Phil does. And when asked about the common componentry between the FJ and XJR motors Phil says the list is shorter if you look at what doesn’t fit rather than what does. “The only things that you can’t swap between the two engines are the barrels and pistons. Although the barrels from the XJR will fit the FJ if the crankcases are machined to take the bigger XJR barrels.” Not that much different at all then.

This XJR is the latest 2010 model, which features fuel-injection rather than carburettors but other than that it’s the same 16-valve motor give or take the few cosmetic adjustments and engineering refinements that are going to be inevitable over the course of quarter of a century. Where the FJ makes 125bhp the XJR motor only makes 100bhp. A backwards step you might think. But you’d be wrong – in the case of a naked bike at least. The intervening years have given the XJR a monumental amount of torque; 80lb-ft compared to 63lb-ft on the original machine. There’s so much torque from the XJR version of the engine that the FJ feels lethargic in the bottom and middle of the rev-range. When a bike has this much torque the five gears are all you need and the first four are only for pulling away. It’s an amazing engine.

Phil explains that the head and cams from the FJ can be fitted to give the newer machine more top-end but he agrees that it’s pretty pointless on a bike with no fairing. He’s right, when a bike has this much low-rev ability it’d be a shame to ruin it.

While I know that in the past this magazine has preached ‘real not retro’, the XJR gives anybody who would like a new bike as well as a classic the opportunity to have a direct link to bikes of the past with more than just a cosmetic styling job. Ride one and see. Even Phil – the most ardent of FJ supports – admits a fondness for the XJR for this very reason.

Buying

The FJ is a great bike that fits the Mechanics ethos perfectly (even if it does have a fairing) because it’s a bike that you can work on yourself. The shims are on top of the buckets, so the cams don’t need to come out when doing the clearances. Phil explains, “The job is easy to do – they’re simple to adjust. If a dealer’s mechanic tells you the valves were checked but didn’t need adjusting then he’s pulling a fast one. Every 8000 miles they do go out a bit. It’s just the way they are. The water-cooled FJRs hardly ever go out but the air-cooled FJs always do.”

Knowledgeable and becoming animated with his chosen subject, Phil touches on the FJ’s weak points, “The front engine mount cracks because one side of the engine is solidly mounted and the other is rubber mounted. Basically, the aluminium corrodes and then the vibration cracks the mount. We fit the rubber mount from the other side to solve the problem.

“If the suspension hasn’t been changed in all those years then fit a Hagon unit to the bike – it makes a big difference, restoring the rear ride height and damping.”

The most common problem with the FJ though is the carbs gumming up through a lack of use – the fuel evaporates leaving a nasty enamel in the internal passageways that can rarely be fully removed. Phil also passes on this advice, “If you are going to buy an FJ get a tidy one to start with. The bodywork is the thing to look at – it gets awfully expensive very quickly if you have to start repairing or replacing it. Don’t worry about the engine mileage though. As long as it doesn’t smoke on starting then it’s fine. These things go on forever.

“If the clutch slips there are only two ways to fix it – get a second diaphragm spring to take up the wear or, the best option, get a Barnett clutch conversion for about £135. It gives a light action but still doesn’t slip.”

Another problem is the rear suspension linkage bearings. In common with many Yamahas from the 80s they seize. But Phil doesn’t see it as a design flaw, “The problem is slack dealerships. They say they’ve greased the linkage during a service but we get so many here at the FJ Owners Club that have never been greased. I’ve also seen new FJRs with only 30,000 miles on them with collapsed linkages too – keep them greased and they’ll almost last forever.”

At a time when the obvious bikes from the 70s and 80s are rising in price it’s refreshing to see that an FJ can be had for relative peanuts. £1000 will buy a tidy machine that doesn’t need much attention. As a commuter, tourer or Sunday afternoon machine, there are few bikes from the early 80s that can hold a candle to the FJ. And it’s quite fitting, although not without a hint of irony, that an engine with its roots firmly in the 80s is now fitted to a bike whose styling emulates the muscle bikes of that very decade. We’re just hoping that Yamaha has a few tricks up its sleeve on the emissions front so this fantastic engine from the 80s will go on for a good few years yet.

Words: Ben Wilkins
Photos: Paul Bryant