I knew things were going to get serious when the handlebars started trying to leap out of my hands. This was the first positive sign I'd had from the Yam's chassis, which normally had a dead feel to it that gave little indication of just what was likely to happen next.
l'd been riding the bike for two days, but most of that time was spent lugging over 500lbs of metal around Central London. It had taken that amount of time to become used to transmission slop, a distinct lack of power below three grand and eight year old front forks that had lost their damping, springing and precision. Using the front brakes had several not so amusing consequences — front fork dive, the bike shoots off into oncoming traffic and pedestrians leap, back in near heart failure mode from the amount of noise the discs make. Who needs horns?
I was following the A4 from London to Cardiff and it was early morning, the sun actually just making an appearance trying to provide some much needed heat, the road was fast and loose, the kind of long curves that the Yam should have been quite happy to live with. It might have been fine when brand new, but a lot of wear in the suspension meant I had to make allowances for its age. There was really too much weight carried too high, for such worn components to keep things under control. As It was so early in the day, I wasn't really paying too much attention, letting the bike purr along between 65 and 70mph, something it was quite happy to do with little vibration and minimum hassle from the suspension
Halfway through a curve the front wheel hit a pothole. It wasn't a huge crater or anything too radical. Most bikes might just twitch slightly. Not the Yam, the handlebars went from lock to look before I had time to realise just what was happening. In the middle of a speed wobble there's not much you can do really, you just sit there with a sinking heart and say a few prayers, waiting to see what happens next. The survival rule is not to press back against the handlebars, because this only accelerates the rate at which the bike oscillates.
Letting go of the handlebars isn't on either, because you need to keep the throttle open, backing off can cause the bike to flip right off the road, although sometimes it does work. The brave solution is to open the throttle and accelerate out of trouble. I let the Yam go its own way for a few yards, keeping just the minimum of pressure on the handlebars, but it just became worse. It was just as well that there were no cars on the road, for the Yam was using two lanes of carriageway. I opened the throttle very slowly to see what would happen. For a moment, I thought the bike was going to go straight through a hedge, but it pulled itself together and straightened out.
For the next fifty miles I cruised along at a mere 50mph. A cursory examination of the bike had revealed a reasonable amount of tyre tread, no loose bolts and only a mild amount of free play in the front forks.
When the DOHC triple was introduced in '77 it was hailed as having the smoothness of a four with better agility and shaft drive thrown in to pander to those not inclined to oil their fingers. The reality was that the Yam was heavier than the Honda CB750, less smooth, equally insecure and much less reliable.
When new the suspension was reasonably firm, and even had some kind of damping. The shaft drive was not exactly remote and could quite upset the Yam on a trailing throttle in smooth or bumpy bends. Throw in some wear and the rear end become very vicious, lurching the back wheel around during power shifts and providing some very weird times in the wet, when the brakes don't bother to work anyway.
On the '78 Yam I was trying to ride, the stock shocks had been thrown away and some 850 units fitted. These benefited from being new and having stiffer springs but were still lacking in damping. Once in a while the shaft drive would wind them up and the poor confused things wouldn't know if they. were supposed to be compressed. or bouncing back. This didn't exactly inspire confidence.
Even though the bike weighs so much. it doesn't seem to help in strong cross winds when the bike starts to wander off course. Riding into strong winds knocks off some of the power available at high speeds. Under such circumstances it's almost impossible to qet the speedo past 100 mph. Not that there's much point unless you really like frightening yourself.
The XS750 is one of the most unsuitable bikes available for riding at illegal speeds. The mass, poor forks and intrusive shaft drive all mean that it's much easier to fall off than go around a corner rapidly. While I'm quite happy to take risks on some bikes to compensate for chassis faults, on the XS I was always worried that the craziness of the chassis would occur without warning, when least expected and in situations where the presence of other road users meant a visit to the hospital was more likely than reaching my destination.
The XS is not dissimilar to the XS650 in this respect except that the triple's engine does not have the same kind of inner strength of the big twin, with neither the reputation of lasting long distances with the minimum of maintenance nor the ability to deliver useful performance despite its handling limitations.
The engine is of relatively straightforward design - by 80s standards, anyway. Despite using DOHCs the engine only produces 64hp — with its heavy mass, the XS can be burnt off by most 550s. The crankshaft is quite a tough roller bearing job that outlasts the rest of the engine. Primary drive is by chain which was worn out by twenty grand on earlier bikes. It makes a fairly obvious rattle and produces a rather sloppy transmission.
The pistons were in trouble by twenty five grand if the bike was neglected and/or thrashed. Well maintained bikes can run to around forty grand, when you really need to throw the motor away because too many components are worn out to make rebuilding an economic proposition. The direct action of the shaft drive tends to destroy both the gearbox and its own bearing joints. Later bikes don't tend towards such self destruction unless they are really screwed along on the red line.
The well used bike I was riding had thirty five and a half grand on the clock, had been rebored once (at 30000 miles) and had a top end that made more noise than the exhausts. The combination of a heavy clutch and a gearbox that was on the way out did not make for a pleasant time. Any attempt to ignore the clutch made for some disturbing metallic screams from the gearbox area and a lurch from the chassis once the gears ground into position. Neutral was impossible to find at a standstill, changes between first and second had a fifty-fifty chance of happening, while shifting down from third to second would quite often put you straight into neutral. This made life rather more interesting and in certain circumstances is a feasible alternative for those who can't get hold of a gun to play Russian Roulette. The gearbox did have a certain amount of feel and by the end of a week's riding it was almost possible to compensate for its worn out condition.
Machines in good condition and of later manufacture have quite reasonable changes, far ahead of BMW twins of the same era and up to the standards of the worst of the 750 fours (Honda). But the back end is still upset by mismatching of engine speed with road speed during down changes in corners.
Top speed of a new bike is around 120mph, but most people will be dissuaded from getting beyond 115mph by a combination of excessive vibes and the dubious handling, that even on flat, smooth, straight roads can switch out of a gentle weave into a nice little tank slapper without any warning.
On the bike I was riding I had no intention of going beyond the ton, not just because I didn't want to die quite yet, I also didn't want to be responsible for returning a bike to its, er, proud owner with the con-rods sticking out of the crankcases. At an indicated ton, there were lots of vibes coming through the footrests and I could have sold a recording of the top end noises to the producers of a war film.
I could find no point in the rev range where the motor really came on cam, it was a bit more useful above 3 grand and out of the ballgame with 7 1/2 on the rev counter, but there was never any real hint of 750cc doing their business — the power was effectively damped out by the 510lbs of metalwork. A low mileage 1980 (last year for the 750) job had a bit more urge at very low revs but was no more interesting at higher engine speeds. The later 850, which has to carry the same mass but develops 79hp, is a rather more useful device, which can give quite a nice kick above five grand.
Riding the XS in the wet is a definite no-no with UK weather this rather limits the uses of the bike... well, OK I exaggerate a little, it is possible to potter along on the Yam in the wet, it just needs nerves of steel and a strong stomach. My main objection is the lack of feedback from the tyres which means there's just no warning of impending doom. On some bikes this isn't so important because the chassis, geometry and suspension all combine to keep the tyres in check. 0n the Yamaha everything works against the rider. There's too much mass, too much transmission slop, an imprecise gearchange, worn out suspension and a dodgy frame. Once the XS starts to misbehave it begins to resemble an elephant in a china shop with the important difference that the china's represented by those nasty tin boxes that tend to destroy errant motorcycles.
I will always remember the time I had to suddenly change direction in the middle of a corner to avoid a Capri that needed half my side of the road to get around the bend. If you've been riding for a couple of years then reflexes take over; you're down through the box, bringing in the brakes, flicking up the bike almost before you've realised there's a hazard. This smooth control of things disappeared when the gearbox found a false neutral and the front disc suddenly broke through the layer of water. While the sudden lack of power sent the back wheel off in a vicious arc, the locked front wheel sent the bike off in the other direction. If I was a skilled speedway rider I may have been able to balance out these forces, but being shit scared I stamped on the gear lever and released the front brake. The series of lurches that resulted ended up with the bike taking up trail riding after crossing in front of a car that was coming around after the Capri.
Sitting on the Yam, there was little choice but to hold on, hope the thing didn't decide to go into a speed wobble, try to lose some speed by shutting down the throttle and, applying some ever-so-gentle pressure to the brakes. Note to the unlucky, to avoid breaking a leg, kick out your leg against the footrest to clear yourself from the bike just before it hits the ground. The XS does not make a good trail bike, one already going too fast and out of control makes for an even less efficient off road cycle. The front wheel started to slide as soon as it met the gravel, when the rear wheel touched home it did a thirty mile an hour slide that demolished some poor farmer's hedgerow. Much to my astonishment the thing came to a halt, leaving a two yard hole in the hedgerow and a rear wheel full of broken branches. The only problem was how to get the bike out without the thing falling over. There were too many branches to use the power and if I got off it was likely to fall over, and I knew from bitter experience that picking up 500lbs of hot metal wasn't going to be much fun.
Luckily, the Capri owner actually came back to see whether or not he had managed to kill me. I suppose I should have broken his kneecaps or something but I was just relieved to find some help. The Yamaha was unharmed and apart from some psychic problems that will probably catch up with me one day, I was unscathed. Having ridden both the later 850 and a nicely maintained 750, I can report that both bikes are a little safer but still not really the; kinds of devices I would be happy to ride fast in wet weather. Something like a Triumph twin or older Norton would make the XS seem the dangerous beast that it really is in the wet.
The X5 is mostly employed as a soft tourer; used within legal limits on good condition suspension it just about survives scrutiny Unfortunately, it consumes tyres and fuel at a far from economic rate. 70mph cruising gives 42mpg, 60mph pottering 50mpg and dodging around town averages 40mpg. Rear tyres are finished off in 4000 miles, fronts in 8500 miles. Brake pads last for 7000 miles. For sure, there are no chains to buy which saves fifteen quid every ten thousand miles and a lot of dirty fingers.
The poor efficiency comes from having the extra twist in the transmission for the shaft drive, an underdeveloped cylinder head design and quick wear internals that lose power due to the increase in friction. The three carbs don't need too much maintenance (say 3000 miles for balancing) but with such a low power output there's really no reason why they couldn't use a single carb.
Anyone considering buying a XS750 will have in approach the bike with great care. There are still some nice bikes around that have engines will lots of life left - especially true for '79 and '80 models. But the good bikes are the exception rather than the rule. A bike that's had a hard life will be lots of expensive trouble.
As well as the mechanical problems there are all kinds of interesting electrical foibles. The coils aren't exactly top notch stuff - difficult starting and misfiring in the wet are the usual signs when a set is on the way out. The alternator burns out due to a faulty rectifier - inconvenient rather than expensive to fix - and all the lights blow out from time to time just to make sure the owner is paying attention. Electric starts have been known to stop working after twenty grand.
Find a bike with a quiet top end and a smooth transmission and you'll probably be on the way to getting a reasonable buy. On hard used bikes just about everything wears out, and despite some tell-tale noises these bikes can often seem to run quite well, so buyers need to know quite a lot about engines when they look over an XS750.
Personally, buying an unknown used XS presents so many pitfalls that I would avoid it with the same kind of diligence I apply to avoiding members of the local scooter club, a device I've avoided ever since I was fourteen and a tree in a friend's backyard had the audacity to step out into my path while learning to master a clutch on a Vespa. Oh yes, XS750s - unlike, say, a Trident (an equally unreliable triple) there is no area in which the Yamaha excels to compensate for its failings in many areas. Having said that, I know a couple of people who have owned them from new, used them in all weathers, haven't been inside the motors and won't listen to my smartarse denouncements - but then, they do very regular maintenance and have cared for the triples with the kind of single minded determination I can only seem to apply to chasing astoundingly beautiful Thai girls.
Given the usual editorial treatment in search of the inner strength of an engine, I fear the Yam wouldn't last for very long, unless it threw me off before I blew it apart...
Bill Fowler