Buyers' Guides
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Wednesday, 20 January 2016
Yamaha XJ900: From new to extinction
Take one perfectly formed Yamaha XJ900, circa 1989, and one hard bitten rider, circa 1950, point in the general direction of the open road and see what happens. That was the plan, anyway, buy a big bike and go see the world. No sooner had the deed been done than I was stung by the girlfriend declaring herself three months pregnant. I didn't know whether I should strangle or kiss her.
I did the decent thing, my reward being allowed to keep the big Yamaha, but world tours were obviously out of the question for the next decade, or more. The XJ was new, needed running in, but this still allowed 60-70mph; wasn't that difficult. A slow blast up to Edinburgh and a faster one back got rid of most of that chore whilst allowing me to come to grips with the bike's characteristics.
One reason I bought the XJ was its shaft drive. No more hassle from dirty chains. The mag's reckoned that the Yam's shaft was one of the better designs on the market, not intruding too harshly into the ride. Well, that was sort of right. I found it very direct, needing very careful throttle control and matching revs to gears during changes. Minor kangaroo hops abounded until it became second nature, didn't notice it any more - took about a month.
By the way, it took about 2500 miles for the gearchange to bed in and another 40,000 miles for the selectors to wear out! The change was quite heavy, needed a slow, deliberate foot and a very fast clutch hand - an odd combination!
My ideal cruising speed's about 90mph, but once the Yam was run in this coincided with some heavy secondary vibes. The ton was an order of magnitude smoother, as was 80mph. I usually opted for the former as the latter had cagers creeping up my backside. The only downside, as the fairing gave good protection and the general feel of the bike was very relaxing, that the ton on the motorway equalled the cops going berserk, whereas 90mph there was half a chance they would ignore you or let you off if you grovelled.
Top speed was around 140mph. At that kind of velocity I didn't have the time to pay much attention to the clocks. Other than on long, straight, deserted roads, everything happened far too fast for me. I was bought up on an era of bikes that didn't want to go much beyond 120mph, and that was fine by me.
What was useful, was the heavy acceleration available in top gear between 90 and 125mph. Could pull the bike out of difficult situations without any need for cog-swapping or any thought other than a willingness to let loose on the throttle. Beyond 125mph the bike began to slow but the motor's power was quite tenacious and would hold on to any speeds gained.
Early XJ's had a bad reputation for handling but, initially, I didn't find any big problems on mine. Mind, it needed plenty of muscle but I was used to these kind of across the frame fours, with their excessive mass spread high and wide. They weren't exactly inherently stable, needed some clever design work to stop them going terminal.
What let the XJ down was tyre wear. The rear tyre, perhaps helped along by the directness of the shaft drive, was in trouble by as little as 4000 miles. It was still legal, in a sort of theoretical and remote manner, but as soon as the tread went below 3mm the stability disappeared. Back end weaves and wobbles went straight through the frame to the headstock, resulting in a good old fighting match with the handlebars.
Worse yet, replacing the tyre with a brand new Michelin resulted in a total mismatch with the front OE rubber, the bike basically unable to make up its mind which way it wanted to go once speeds above 80mph were indulged. Turned out that every time I replaced a rear tyre I had to get a matching front even when the makes were the same and there were many thousands of miles left in the front.
You can tell a lot about the inherent stability of a motorcycle by the way it runs on worn rubber and it was easy to conclude that the XJ900 was totally lacking in any depth of chassis design. Come 21000 miles this was further emphasized by the steering head bearings going down, producing some really vivid speed wobbles that are firmly wired into my brain.
No sooner had the head bearings been done than the wheel bearings went, another fine handling mess. Replacement bearings, even though they came from the nearest Yamaha dealer, didn't last for more than 15000 miles.
The brakes were another element that constantly annoyed. Fine when they were new, or at least after a couple of hundred miles of bedding in, once the guarantee expired and winter riding set in, the calipers began to seize on and I was never quite sure how the pads would react to wet weather. A very spongy feel at the lever soon developed. Before 20,000 miles was up, a complete brake refurbishment was necessary. An hassle thereafter repeated every 9000 miles, or so.
Actual pad life varied greatly depending on the kind of riding I did. The most I ever got from a set of front pads, 11000 miles; the least 4500 miles. EBC's suited the bike best but lasted less well than other makes. By 37000 miles a complete set of front brakes was bought from a breaker, from a nearly new XJ900. These were a bit fiercer in the stopping department and not so susceptible to winter riding; Japanese brakes have improved over the years, recent stuff much less likely to give serious hassle. The rear brake wasn't used much as it seemed to react against the shaft drive on the overrun, did nothing for the stability in corners (neither did the front brake but that was expected). Sometimes, I didn't notice it was all seized up for a couple of weeks.
Comfort was another facet of the bike that went off with age, basically down to a combination of the seat going all soggy and the suspension losing most of its springing and damping. The seat was easily fixed with a rather tasty K & Q item that gave a very plush perch and had the wife singing the bike's praises. Even new, the stock saddle produced some backside pains after as little as 70 miles in the saddle, although my backside did toughen up a little and soon wasn't complaining until at least 100 miles. In long distance cruising terms this is just a joke but easy to fix.
The suspension started out as a good compromise between firmness and suppleness but even before the guarantee expired the back end had turned a little soggy. Once the suspension starts to go, the weaves set in and it's an urgent trip down to the nearest store or breaker. A set of adjustable R & R shocks found in the latter, for forty notes. These were the right length but took about 10,000 miles before they lost the ultra hard feel; must've been designed for some really heavy monster.
By the time I'd bedded in the shocks the forks had gone all mushy. Never the firmest items in the history of motorcycle manufacturing, they now dived with a vengeance when the discs were used in anger and went all deranged when accelerating out of a bumpy corner. I'd already added a hefty fork brace, which hindered as much as it helped. A friend had blown up his FJ1200, had a much modded front end for sale...
Unfortunately, this didn't include the front wheel or brakes, which might've solved another problem. After some hassle with the yokes and brake lugs, the new forks were fitted. The bike feeling totally transformed, though it needed even more muscle to shove through the bends. The XJ was almost up to modern cut and thrust standards, though you had to watch out for all the mass catching the chassis out and biting back in a big way.
Writing this makes the bike seem a lot of hassle but the problems turned up over years of riding, were spread out rather than concentrated in a short period of time. Most of my experiences with the Yamaha were a lot more pleasure than pain - honest!
The XJ was heavy and slow turning, sometimes susceptible to road imperfections, but it was also very versatile. Once used to its machinations, I was able to muscle my way through town, cruise down motorways and play around on my favourite curvy back roads.
Use of the gearchange was optional. Often I just stuck her in top gear, did the throttle blues and enjoyed. The gearchange wasn't exactly slick but it didn't really hold any terrors until the selectors wore out. Then it just became a bundle of false neutrals which by 45000 miles was almost impossible to use. Used selectors off a nearly new XJ were fitted, but these needed a bit of file work, so Yamaha had evidently 'improved' the box over the years.
The gearchange never regained its former smoothness but at least it now clunked into the required ratio without threatening the dreaded, and embarrassing, false neutral. Nothing makes you look more of a plonker than screaming an engine at unlikely revs in the middle of town.
This was the first serious engine problem, but presaged some other hassle. The bike had the valves and carbs done every 5000 miles, plus very regular oil/filter changes and was always given a good burn out every time it was ridden. Big bikes, like large dogs, always need regular exercise. Lack of attention to the carbs and valves meant an increase in secondary vibration and a distinct lack of urge at the upper end of the rev range.
The first item to go on the engine was the camchain, at 51000 miles. Presaged by an excess of rattling that no amount of tweaking with the tensioner could remove. Once the rattles arrive, change the camchain pronto. I didn't, resulted in the damn thing breaking! I was lucky that the valves and pistons didn't mesh and unlucky in that I had to push the bastard three miles home. Could've been a whole lot worse.
Again, used but nearly new components were fitted (including the camchain tensioner which had been flayed down by the chain whipping about). Some quite heavy wear on the camshaft lobes noted at this point but nothing done about it as the kid had financial priority. Plenty of crashed and bashed XJ900's in breakers, they can catch out inexperienced riders who aren't up to coping with their mass and power.
The finish was well gone, little chrome or alloy left unblemished, with large patches of paint bubbling with the rust. The exhaust had actually survived but not without some internal rusting and ruined downpipes (at least externally). The whole bike was quietly drifting towards rat status but I decided to fight back.
Breakers were visited, nearly new cycle parts bought. I was, anyway, worried about the petrol tank, which had gone very thin on its sides and needed the fuel filter cleaned out every other week. That just left the wheels, engine finish and frame paint to sort out. Only the latter was done as the alloy corrosion on the other parts proved impossible to shift. Still, the bike looked quite respectable and the replacement parts were very cheap as the breakers had excess stocks. Always worth making a silly offer.
The exhaust system lasted a few more miles until the rotted baffling and holes in the silencers conspired to upset the carburation, not to mention a large amount of banging on the overrun. Fun in a nervous capital. Plenty of 4-1's on offer, new and used, but the neighbours already had me on their death-list so I opted for a used stocker from the breakers for a reasonable seventy notes. Given that there wasn't a spot of rust on it, made a major difference to the appearance, as well as getting the engine's juices flowing.
The mileage crept up and up, passing the 70,000 mark without any major incident - plenty of minor stuff but that has already been covered. At this point it became apparent that the insulation began to fall off the wiring, starting became a hit and miss affair, and the lights would blow when I least expected or wanted it to happen.
I had loads of fun with a secondhand wiring loom as it seemed off a whole different bike, but I got there in the end. Later switches were also fitted. Both the alternator and black boxes all survived the demise of the wiring, major expense and inconvenience avoided.
I wasn't sure if all the effort involved was worth it as at 72000 miles the engine began to lose power and produce heavy smoke. Rebore time. The aforementioned camshaft lobes had also lost a lot of their hardening... in fact, the whole top end looked pretty shagged. So more begging sessions with a breaker. I should've gone for the replacement engine option, which at 450 notes wasn't anywhere near as expensive as I'd expected, but as I had the old one apart I decided fitting a newer top end was the easy way out. 130 notes was all it cost, though I had to source the bits from three different breakers.
XJ motors are quite fiddly to work on but a weekend's hustle had the bike ready for the road. Performance improved and the smoke was just a memory but it wasn't up to the standards of a new bike, didn't really want to know about more than 125mph. Still a very useful tool but not one in which I had much faith.
The economic side of the XJ wasn't very convincing. When it was new, fuel averaged out at 37mpg, in its current state that was closer to 30mpg. Tyres were very short-lived, brake pads variable. There were some savings made from the absence of a chain, but with modern O-ring chains that didn't add up to a huge amount. Long distance touring could do serious damage to the bank balance.
Even bigger damage was done when the engine finally expired. It was one of those really sultry summer days when you can really exult in motorcycling and I was giving the XJ some serious stick in third gear. Not enough to break into the red but more than sufficient to have the secondary vibes singing through the chassis.
Then the motor stuttered, the next thing I knew it had locked up solid with the back wheel going into a massive skid. It was an easy way to lose one's dinner out of both ends. Quick as a flash, I pulled in the clutch lever but that had no effect. Next, maximum muscle on the brakes, pulling the bike up whilst the back end skipped from side to side. It was all so violent that there was hardly any rubber left on the back tyre. I must say, though, that the XJ was more stable than I would've expected.
The expense arose not so much in the motor destroying itself as in the fact that the following cager had totally lost control of his Audi, something to do with the wild Yamaha's antics giving him an heart attack. The momentary relief that came from making it to the side of the road in one piece was dissipated when I glanced over my shoulder to see several cages piled into each other! The plod had a fine old time, especially when they realised my insurance had expired!
The XJ was eventually carted home in the back of a mate's van, the engine dismembered. The cause of the seizure had something to do with the gearbox breaking up but there was such an excess of damage that no really clear point of failure could be established. There was very little left that could be salvaged.
By the time I did the rounds of the breakers there weren't any decent engines left. I took a chance on a 55000 miler for 250 quid but not a very good unit, smoking and rattling. Okay for hopping around town but after the last experience I didn't trust it at speed.
The bike cracked the 80,000 mile barrier but bits from the original chassis were showing signs of dying from fatigue. Stuff like hairline cracks in the rear wheel's hub and rust seemingly breaking out from inside the frame tubes, added up to an accident about to happen. The breaker gave me two hundred quid for it. A sad end.
George Irving