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Classic Motorcycle Review - Posted 28th May 2010

1975 Yamaha XS650C

Back when winter's chill still laid upon the land, Karl Bentley took his classic 650 twin out in search of straight roads in the Kent countryside...

At last! Sunday morning, the first Sunday of the holidays. I've been waiting for this day for a couple of months. The bikes have been laid up in the garage due to work commitments. But that is behind me now and I spent yesterday afternoon fettling a couple of bikes for today's ride. It's a late start this morning as I downed a few celebratory pints last night.

The bike I've chosen for this morning's ride is my faithful 1975 Yamaha XS650C, the last of the roadster XS versions. In my opinion, having ridden earlier XS1, XS2s and the later Customs and Specials, I have always though that the B and C models were the best handling variants. Mine handles fine in the dry and admirably in the wet, but the aging Speedmasters are making life fun on damp roads, roads like today's ride promises to bring. But I have a reason for choosing the Yamaha over my other mounts, the R80RT and assorted MZs (the A50 Royal Star not being in the running as it's in a million bits strewn about the garage at the moment).

XS650: A barrel of laughs... 1975 Yamaha XS650C

I recently changed the Yamaha's engine sprocket from a 17 tooth to an 18 tooth sprocket. Now that may not sound like much but the XS has always been vibratory at 60 and above and has always felt like it was revving too high too soon. A bit of internet research led me to discover that other folk, mainly our American cousins, felt the same way. There is a huge XS650 following in the States and some good internet sites full of ideas. So a call to the XS parts suppliers in Germany (another big market for the XS) and I soon had a one tooth bigger sprocket. A few quick blasts on the motorway proved the pudding as it were and 70 is now a more relaxed and hence enjoyable affair. But this is not what I think XS650s are about. No in my opinion this is a true A-road hustler and I wanted to make sure that the bike had not lost any of its low down grunt in return for a more relaxed high speed gait.

So with both petrol taps on and the left hand lever pushed down, it's a fuel enriching choke and it comes in to play on both carbs together as, along with the throttle, the carbs are connected by linkage bars. One for the choke and one for the throttle. This was a neat solution to the problem of keeping the carbs balanced; a pity more British bikes don't utilise the same system. Another benefit of this being only one throttle cable to change, but as XS650s came with CV carbs the action is light anyway, so the cable doesn't take a lot of strain.

XS650 choke mechanism: Simples!... 1975 Yamaha XS650C: Linkage rod runs between carbs to sychronise choke mechanism

The bike takes several kicks to get it going, which is odd as normally it's a two or three kick affair, even from cold. Now that should have set alarm bells ringing, but I put it down to a cold morning and petrol that's been sat in the bike for a couple of months. Luckily it's getting on for midday, as the exhausts make a lovely roar as the bike fires into life, don't want to upset the neighbours now do I?

I drag the bike back off the drive and onto the road. It's a lump to lug around and always feels heavier than it should and it's at times like this that it makes its mass felt. Having said that it comes up on to its centre stand very easily and at least it has a side stand that you can pop down from the saddle unlike my Beemer or MZs.

Snicking down into first gear reminds me how good this gearbox is; it really does 'snick': the only downside being that the clutch has to be adjusted just right to find neutral once the motor has warmed up. The old trick of making sure you drop into neutral before coming to a stop is a worthwhile habit to fall into on this bike. The clutch itself is fairly light but I have a feeling that it doesn't disengage the plates enough to stop a slight drag once warmed up, hence making neutral hard to engage.

Some RealClassics, yesterday...

Out onto the main road and I plot my course to avoid the Sunday shoppers out by the ubiquitous, every town must have one, outlet centre. A mile or so later and the choke comes off and the bike is burbling happily at the first set of lights. This reminds me that the last time I rode the bike, months ago, the tickover had been wandering, I shoved this thought to the back of my mind as the lights go green and I pull very carefully away, off and around on very damp and far too greasy roads. This pottering is okay as I like to warm my bikes up before I give them too many revs.

Up to forty and the next roundabout looms up. This is a notoriously dieseled up roundabout so I pull on the front brakes gently to bring my speed down before I get to the roundabout. This reminds me how wooden the brakes feel. It's not that the brakes don't work, more that the master cylinder is not sized right. I have another, later, Yamaha brake cylinder to replace it with at some time over the winter. It's a recommended change but it all comes down to personal choice and how you like your brakes to feel.

Once safely round I twist on more gas and the sound rumbles up to me. The bike makes a glorious sound, not a noise; no, this bike definitely makes a sound not some annoying noise. Out past the last of the shopping centres and down the A28, I soon turn off onto the A20 in the direction of the William Harvey (famous for?) Hospital. Before I get there I pass the Julie Rose (who?) stadium and my nose is assailed by first the soup smells of the Batchelors Cup-a-Soup factory and then in direct contrast past the rather more aromatic smells of the Quest perfume plant.

There's chalk in them thar hills...

But that's Kent for you, a huge county full of opposites. From ancient Canterbury to the rash of modern housing; industrial blots next to lush country side; chalk hills rolling down to rolling seas, a beautiful county full of marvellous Kentish lanes. However, it is not a lane I am aiming for today but a road. A road I first noticed on an Ordinance Survey map. A long straight road, a Roman road.

I love looking at maps and if you every look at a map of Kent (where the OS maps were first drawn up in 1801, to site guns against a possible French invasion) you will notice something odd about the old road system. Most of the old roads run East and West and it is only the new roads and railways that run North and South. I'm not going to tell you why, as I'm not in teacher mode, so I'll let you find out for yourself.

Back to the A20 and I can let the bike come up the 50 and 60 limits and it's just humming along with no vibration and pulling away from bends and obstructions, without any detectable loss in pulling power felt from the recent sprocket mod. The sun is warm on my back and it casts long shadows, even though it can only be midday, in front of me.

I'm looking for place to stop and take pictures but there are no lay-bys, pity as the scenes across the Kent Wealds are magnificent in the clear bright winter sun. Soon I'm up to the M20 or the lorry park as it's known down here and it's time to turn off onto my chosen road. The B2068, better known as Stone Street.

The first part is uphill, which the XS takes in top and round a few coppiced bends, the trees were coppiced once for the metal industries charcoal burners that once thrived here. Then it's up across the North Downs way and then over the Pilgrims way and I'm up and on to the Kent Downs.

Stone Street...
Classic Stuff on Now...

Now the road straightens and as the bike comes to a rise I can see it stretching ahead, not arrow straight but pretty near. Even though the road is fairly straight the approach of Six Mile village brings the speed limits down. Still, even though I am the only road user except for a car a mile or so ahead I feel no need to press on. The day is too pleasant and I'm in no rush to get anywhere and instead I enjoy the rolling rumble of the bike under me. Signposts to villages drift past: Stelling Minnis, Bossingham, Waltham, Petham, Lower Hardres and then Chartham. All good old Anglo Saxon names: 'ham' designating a village or homestead and 'Minnis', etymologists will tell you means commonland. Which means 'Stelling' is fairly unique in surviving the enclosures that drifted on from the 1600s to the mid 1800s around here. Hardres, well that is just to remind us that not far way in 1066 a bunch of Normans arrived and Hardres was one of them.

All too soon I come to the end of Stone Street, just past the aptly name Street End village and the traffic starts to thicken. This is no surprise as Stone Street was a direct route to Canterbury from the South coast and soon I am pottering around the thirty limits on the environs of this beautiful Cathedral city. It is here that I play with the gears to see how much the sprocket change has affected the low down pulling power. I come to the conclusion that it hasn't as I turn off and along the A2050 and into the city.

In fact the gearing change has made the bike softer and less rev happy and has turned a light-to-light bruiser into a much more pleasant machine. But has it lost its grunt altogether? Well as always, there's a boy racer trying to muscle in, so at the next roundabout I give it a bit of stick and nope, the bike's lost none of its grunt. I reach the next roundabout with the muppet's bass and woofer booming well behind satisfyingly drowned out by the Yamaha's own brass section. I had thought I'd be slipping the clutch more but in fact I do it less as I'm changing up later.

The brass section...

Time to leave the city and I swing off the ring road, taking note of the ever-present speed camera, then I leave the shoppers behind me and I'm out onto one of my favourite roads the A28. I know this road well but I'm cold and need a break. My new gloves have kept me warm but I need a break and so diverting off onto the A262 I stop off at a rather peculiar trinket and animal farm in Chilham. Checking over the bike there are no oil leaks and everything looks sound. So I amble inside order a milky coffee and retire to the bizarrely decorated greenhouse, warmed by gas fires and surrounded by glass and crystal ornaments and bric-a-brac, inside and out of this bejewelled palace.

The sun is starting to drop down to tree top height but is still warm through the glass walls as I ponder the rest of my route. The A262 has some fast stretches so I think I'll give it a bit of stick as the roads have dried and there is little traffic out today. Drink finished, bones warmed and once a couple of pictures are taken, I tog up. The bike fires first kick as it normally does warm. Out onto the road and I'm slowed by signs saying slippery surface. Hmm, this road was resurfaced last year with that new super gloop and you can see it has flattened down to a shiny dead flat surface. What idiot decided to resurface our roads with this rubbish?

But soon we are out onto better gripping clear dry roads and I let the bike go; now I wasn't speeding, I was making progress, as my IAM observer used to say! The bike flies from bend to bend. It needs more pressure on the bars than modern bikes but the wide bars give more leverage and soon I am through Challock, Eastwell and then in a flash I'm into Charing and out and turning left I'm back onto the A20. Now I can really make progress as the road widens and soon cars are passed and left far behind.

Then before I know it I'm thundering back into Ashford but as I back off, the bike hiccups and falters nearly stalling at the Cow Roundabout. The roundabout has silhouettes of cows in the middle of it, I don't know why and I really haven't been bothered to find out yet. I hastily swap over to reserve on one of the taps and the bike picks up cleanly. Hmm, just petrol running low maybe? I'd planned to go around the back of Singleton Hill to get back home, so I divert up the A28 and off into Great Chart.

The bike is running a bit flat and as I pass New Street Farm it dies on me, luckily on a straight clear country road. I drift to a silent halt. Hmmmmm…

Normal service will be resumed shortly...

Now I know I have electrics as the lights work and the bike is trying to fire on one pot. I check the tank, plenty of fuel. The carbs were stripped and cleaned in the summer, hmm. I've worked on this bike long enough to know that it felt like an ignition fault. More, mmmms. I had a dodgy mechanical regulator and it caused me similar problems. But the new electronic one seemed fine, I pulled off the side panel and it feels warm but not hot. Hot or stone cold would have been a bad sign.

Fortunately, I have a toolkit on me; I always have a toolkit with me for rides out of town because you never know, do you? So it's off with the points cover at the top of the engine, which now covers the Newtronics electronic pickups. As I check the pickups I notice that I can turn the timing disc round on the end of the camshaft. So that's the problem! The little grub screw has turned into the little grub un-screw and allowed the disc to turn. I guess it's been loose for a while; luckily the screw didn't fall out!

Little Grub Un-Screw, arrowed...

With the aid of small screwdriver and gently turning around the disc I soon found out where it had been located originally, indeed there was a drilled hole for it. Kicking over the bike it fired up first go and settled into a steady, if fast, tick over. Covers back on and tools back in the bag and we are off again and once up and over Singleton hill I'm soon home.

Time for a coffee and to get the timing strobe and tools out, but that's another story and then of course, another ride…

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