Suzuki 250 X7
Speed at the low end of the market often means two-strokes. And a lot of the fun comes from running them on spannies with a touch of port work. Not too extreme, mind, otherwise the engine starts clogging its plugs in town and needing a rebuild every other month.
One of my all time favourites was a Suzuki 250 X7. Out of the crate it was a pretty hot number, one of the few 250 twins, back in the late seventies, to actually do a genuine ton. I've seen 110mph on the clock - flat on the tank thanks to clip-ons and rear-sets...and a quite mildly modded mill, more a higher compression ratio than radical ports.
You have to be very careful with the port work because if you take too much metal out the piston rings will break up. Sometimes the bits go straight out of the exhaust, other times they end up playing knock-knock with the bottom end.
Besides, with wild port work the engine's really reluctant to run below five grand - fine if you keep it on the throttle all the time, making the power kick all the more startling, but somewhat tiresome after a while. There's no reason why a well sorted stroker, especially one with reed valves, can't be pleasant, reliable and fun.
Degutted stock silencers work just as well and are a cheaper if no quieter option than spannies. Suzuki had been churning out these style of twins since the sixties and had perfected the exhaust dynamics, only noise laws held them back a little.
One reason the bike goes so well is its lack of mass. Under 300lbs which makes the chassis rather edgy at the upper limits of the performance. After an accident both forks and frame can quite easily end up bent - both can fail catastrophically if straightened - they are marginal even when perfect. Don't be put off by a bike with a non-standard front end (twin disc set-ups are popular) but make damn sure the frame's okay.
With the aforementioned front forks and a pair of Girling or Koni shocks, the X7 can be flung around with great alacrity. It's not that difficult to give RD250LC's a run for their money. Straight line stability's always going to be nervous at speed, sometimes camel-like. That's down to the short wheelbase and junk swinging arm bearings - a nice alloy swinging arm really does make a difference.
Good engines should wheelie in the first three gears, have a slick gearbox and not rattle or knock unduly, although pinging and piston slap were there from new. Vibration's another sign of potential disaster, although a bit of buzzing at the upper end of the rev scale's quite normal.
Excessive vibes means the main bearings are on the way out. They can be short-lived on heavily tuned examples, as can the crank's seals and small-ends. Smoke out of the exhaust isn't that accurate an indication of engine condition, as they all fumed a little. Obviously, if it gets you coughing then something's wrong. It's always a good idea to keep a weekly eye on the oil pump as they can go awry.
The X7 has cheap insurance, reasonable running costs (40 to 60mpg) except for chains and an eye catching style in addition to the sheer thrills of its stroker power kicks. It will grumble through town without immediately oiling its plugs but the way the motor surges indicates that it wants its unruly head.
Learners used to be able to jump straight on them and fall off with ease; even 125 graduates will still find this seventies stroker a bit on the hard side. £500 should buy something rather neat, they are available for less but are so far gone that they are more trouble than they are worth. Properly rebuilt engines should last for 15 to 20,000 miles.
Older stroker Suzuki's in this price range exist, cute things like the Ram Air GT250, but age hasn't been kind to them and by the time they've been tuned for the ton they prove very unreliable. Avoid unless desperation sets in and their looks get to you.
Yamaha RD250
The old air-cooled RD250's are another way into the speed game, often preferred over the X7. The engines are a bit notorious for eating their reed valves (replace every 10,000 miles with either stock or Boysen, some of the cheaper varieties are nasty) but that aside they can be significantly longer lasting than the X7, when tuned to similar levels of performance.
They can also take a heavier port job and prefer a set of spannies to the OE exhaust. The reed valves help maintain some low end urge even with an over the top tuning job, which allied with clip-ons and a race fairing can put 115 to 120mph on the clock. Pretty good going for an engine that stock only manages 30 horse and a mere 95mph. Actually, a pure stocker's such an amusing and friendly device that it's worth sacrificing a little top speed to enjoy the original experience.
The frame is superior to the X7, both in strength and geometry, based as it was on Yamaha's race track experience. Like the X7, the swinging arm bearings are a weak spot but a decent set of bearings and clip-ons give good stability without ruining the way it can be flicked through bends.
Fork and brakes are better, too, but again the effects of age, British winters and the inevitable crashes means most stuff has later, superior front ends off whatever's available cheaply and looks likely to fit. The frame can take being straightened out a couple of times. To be fair to the X7, the RD's 50lbs heavier and harder going through the bends.
Reliability and longevity's very variable. Like most strokers, regular ignition timing checks are necessary (if you use fag paper and a finger in the wind chances are you'll end up with holed pistons). The RD series runs better on electronic ignition but often the vibration destroyed it, which can turn out to be a very expensive indulgence. The electrics are similarly on the marginal side, so check for wiring and rectifier bodges.
Generally, the later the model the better it works, although few have been left as the manufacturer intended and bits are mixed and matched between models. There's no way of sussing how well this has been done other than riding the thing - look for wheelies, a very strong power kick at six grand, a smooth transmission and steady running at low revs.
The engine does go through spark plugs - it's worth pulling the existing ones out, both to check their condition and that the threads haven't stripped (although an helicoil repair ain't that big a job). Cylinder studs can also strip, teeth fall off gears (and the selectors are a bit iffy) and carbs wear out (become impossible to balance, which ruins the way it runs at low revs and can turn up a lot of vibration - if you're sure it's the carbs you can bargain the price way down by suggesting the engine's on the way out).
Heavily tuned engines can need attention every 10,000 miles (or even 5000!), mildly tuned ones do more than twice that. In both cases needing an exchange crankshaft and new pistons. There are loads of racing parts available and whole books written on tuning them.
£500 doesn't buy too much, these days. £750's more like it and the odd one goes for truly silly money. Some say the RD250's a classic and in its way it is - as the ultimate development of the air-cooled stroker. But don't let that put you off as it will certainly hold its value much better than other strokers. There's also an RD350 which is a bit fragile and is too rare to worry about here.
Kawasaki KH250
The triple represents the savage and heroic school of speeding. Although the 250's relatively mild compared to the fearsome H1, of which legends and broken legs are made, it still has some wild and wacky ways. Kawasaki triples are, of course, famous for their handling, or rather lack of handling...
The KH (in contrast to the earlier S1) had sort of sussed the geometry and suspension, and tuned out the violent power pulses that upset the original chassis so much but once a little wear got into the frame bearings and suspension all the old horrors came back with a vengeance. In bends the thing could wobble all over the place; backing off the throttle intensified the back wheel's attempt at disintegration, causing the bike to run wide into traffic. Okay, a lot of the hassle was caused by the way the harsh acceleration lightened the front end and a set of clip-ons halfway down the forks did wonders for stability if not spines.
Most engines were tuned to the extent that top speed matched the original model's 100mph (this back in 1972, so quite impressive). The key to extracting good performance, a degree of civility and reasonable reliability is retention of the stock airbox. Far better to puncture an old one with a screwdriver than fit non-standard filters, although both those solutions can affect bore/piston life (which is short to begin with). The reason for this is that triples are notoriously difficult to cajole into running smoothly, with their odd firing pulses.
Poor running's also caused by old (as in 500 miles!) spark plugs and HT leads that, stock, weren't made to withstand British weather. It's almost inconceivable that these won't be in fine fettle on a bike for sale, but you never know your luck - one friend managed to pick up an S1 for £150 that was fixed with new plugs and leads! He fell off a few days later, so it wasn't quite glory all the way.
Often S1's and KH's, to a lessor extent, burn holes in their pistons through neglect of the three sets of points - they really do need doing every 500 miles! Later CDI units need extra rubber mounting to stop the vibes getting at them and can go at any time!
The 250 triple does vibrate a bit at the top end and sort of grumbles with discontent at low revs, although in standard tune there's a surprising amount of torque that belies their reputation as a rice burner. Even after a rebore and new pistons, there's lots of rattling and slapping; enough to hide the main's knocking or the small-ends going.
Overall, it's not impossible to set one up for safe riding whilst a mild tuning job gives plenty of kicks. But most examples are very ragged, more trouble than they're worth unless you are particularly taken by the looks, reputation for madness, and sheer outrageousness of their design (and many people are).
For the same kind of money (£500 to £700) a really nice X7 or RD can be found, both of which are better served by used spares, tuning expertise and general lore. For those after real madness, the H1's better.
Honda CB250K1
In terms of performance, Honda never made a better 250 twin than this late sixties bolide. Even then it wasn't quite up to burning off the strokers but the simple expedient of a Read Titan 325cc big bore kit gave the bike a much nastier edge than the identically sized CB350K, which was much more of an old farts' hack.
The K1 could just manage the ton (you know, following gale with long down-hill road). Bored to 325cc and fitted with clip-ons 100mph came up with much greater ease; 110mph on the clock was possible. Not only was the bike faster but there was more midrange torque. The substantial increase in vibration was the major downside...
Those who like these kind of bikes would describe it as raw, full of character; those more used to modern Jap iron, as a vibratory old heap. Either way, it's something that's easily assimilated after a few hundred miles in the saddle and the vibes don't destroy any engine components.
The buzzing can wreck batteries (just wrap in old inner-tubes) and the rest of the electrics (naff lights, dubious rectifier, etc) benefit from an upgrade to more modern components from current Hondas courtesy of the nearest breaker.
As do the brakes and suspension. Certainly, if you're going to revel in speed then the front forks (especially the wholly inadequate bottom yoke) and TLS drum (which cracks up after twenty years) have to be dumped. CB400N forks and twin discs seem a popular option, although the Comstar wheels looks naff in the context of the CB250K1's simple, classic lines.
Even in 325cc form, the mill's quite tough, although many of the conversions have a penchant for blowing their head gaskets. This can lead to the cylinder studs stripping their threads when some lout over-tightens the head nuts! However, even reasonable motors leak oil from the cylinder head gasket!
Another common malaise on this Honda, and many other models from the same era, is the rubber carb manifolds cracking up. Just the slightest crack causes one cylinder to refuse to run (at best, at worst it holes the piston with the ultra-lean mixture). If you don't know about the fault it's really easy to overlook and spend weeks trying to solve the problem. They can be repaired with silicone and bonding a bit of old inner-tube around them. Also carb diaphragms are notorious for cracking and some may've been repaired with Superglue (a better fix is to cut up a car carb diaphragm to fit if you can't afford new Honda prices).
If you find any old Honda twin with a slick gearchange, buy it - they weren't that good when new and went off rapidly with age and mileage. Don't be too put off, though, rather like old boxers the change's an acquired art; practice makes perfect.
There are some very well sorted 325cc K1's out there, which means 500 notes on a good deal. Less money can buy a lot of trouble or a reasonable 250 version; serious dosh an original example that needs lots of work for speeding. The later K3/4 are too slow but can also be pepped up with a 325cc kit.
Yamaha RD125LC
These old twins, above, are all very well but age limits their availability and ultimate durability. In some ways, derestricted 125's are a better option. The major limitations are that top speed's nearer 90mph than the ton whilst highly tuned stroker singles become very finicky when pushed to the limits.
Of all the models available for around 500 notes the RD125LC stands out as the one to go for. It's possible, if foolish, to spend twice that for a really nice one. Hardly any have been left in stock condition, so they should be ready, straight off, to rock and roll in the fast lane.
It may be surprising, but compared with a derestricted TZR125, the RD is actually harder charging although the undoubted superiority of the TZR's Deltabox chassis gives it an edge in the corners. Unfortunately, a lot of RD's were crashed and bashed; its tubular frame not the heftiest in the known world - check wheel alignment for straightness. Even that won't give the whole picture as some top frames were cut and welded. If you have the faintest suspicions insist on whipping the petrol tank off.
The RD has a peach of a stroker motor, the watercooling and good build quality (Yamaha have always been the leaders in two stroke technology, with only Suzuki sometimes equalling them) making it safe at 25 horses; only showing some limits when power's pushed towards the 30 horse mark. In other markets Yamaha still make air-cooled motors that make 25 horses; it's only our silly learner legislation that makes such power to cubic capacity ratios seem so dangerous.
The mill responds well to spannies and a K & N filter, although it's easy to get the jetting wrong and burn a hole in the piston. A wild porting job and increasing the compression ratio lift the power 2-3000 revs up the range and make the red-line entirely theoretical. The watercooling has to work overtime to keep the mill from melting down but unless you indulge in a 90mph spree for a couple of hours then it succeeds.
The RD has a reed valve that's really rather good, worth retaining if a modicum of low end torque's needed for town work - useful as it dims the racket out the spannie, thus placating both the cops and the MOT tester. In this tuned, highly stressed state I'd recommend replacing the reed valve every 10,000 miles as it's a lot cheaper than doing an engine rebuild if one breaks up and goes on a tour of the engine.
Of course, an RD125LC, tuned to heaven ain't going to last so well as a stocker but bear in mind that's it's a relatively easy and cheap motor to work on. I reckon somewhere between 15 to 20,000 miles for an engine capable of pushing the bike to 95mph. One that does a genuine ton won't last for much more than 10,000 miles.
The engine's most likely to fail in the piston ring area, but all the crank bearings can go as well. Really heavy tuning has been known to break up the gearbox but at that level the bike's almost impossible to ride on the road, such is the paucity of low end and midrange power.
The chassis was reasonable when new but mileage, abuse and neglect can all take their toll. Both on chassis bearings (the rear mono-track's a pain in the arse), suspension and brakes. Most bikes will've been upgraded along the way but there are some odd chappies who insist that a speed wobble's all part and parcel of the high speed game. Check the chassis well.
Because of the learner laws many RD's have been kept going way past their prime (40-50,000 miles). However, it's pretty obvious which are the good ones from the way they run, smoke and sound. You can have a hell of a lot of fun for very little money or a little bit of fun for a hell of a lot of money.
Suzuki GS400
Perhaps it's safer to stick with the four strokes after all! Few are safer than the GS400 and 425, which are so alike as to be identical. Well, almost, the 425 version having a tad better top end. Early examples of the GS being prone to burning out their exhaust valves. Care has to be taken in matching jetting to non-standard exhausts, especially the straight- thru 2-1 variety.
The GS doesn't look fast, even verges on the bland, but that's nothing a matt black paint job won't fix. The latter necessary, anyway, as by now fifteen plus years of abuse will have finished off the original paint. Shockingly, some examples are still around on their original suspension which only shows that the frame and geometry were well thought out.
As unlikely a contender that the GS might be, it has to be considered on two fronts - it's cheap and with very minor mods will touch 110mph. Those mods are a freer exhaust, jet kit, K & N's plus a set of drop bars and rear-sets. The rather remote, if not regal, ride's fixed with stiffer suspension.
Thus transformed there's a bit more tiger than terrier. Coupled with an engine so tough it can be abused for a good 50,000 miles before a rebuild's needed. An engine on the way out's easily recognized by roughness, a shot transmission and a camchain that sounds like it's auditioning for a spot as a chainsaw.
Ah, I hear you all scream, what about the bloody electrics, then? Well nasty! But only as stock, by now they will all have rewound alternators, non-standard rectifier/regulators and a complete rewire. Done properly, no problem. Bodged, all kinds of nastiness happens - cutting out, blowing bulbs, exploding fuses, boiled batteries, etc. All the problems can be solved, Superdream rectifier/ regulators being a popular option, so take a bike with failing electrics as an opportunity to cop a bargain.
There was a GS450 version for a year, which was more of the same and not to be confused with the later GS450E. The GSX400 shared the same bottom end but the eight valve head tended towards self-destruction when ridden hard. It may or may not be possible to fit a GS top end if you find a cheap one. Otherwise, ride slowly. £500, or less, can buy a very nice GS400/425.
Honda CB450
Another balsy vertical twin, the infamous sixties Black Bomber, despite editorial blessing, is too rare on the ground to be of interest here. Either ending up exploding in a big way as a result of high mileage (50k plus) or in the garage of some classic nutter - why can't they stick with British bikes?
However, the later seventies version, now being imported from the States in reasonable numbers, has the goods for speeding and crops up in need of minor if time consuming cosmetic attention in the £500 to £750 price range.
The main thing is to make sure the mightily complex DOHC engine's in good fettle. The cylinder head's especially complex, needing the valve clearances set every 500 miles. Dropped valves are caused by either using too many revs (stick below 11000rpm, the power's all gone by then) or poor assembly of the rockers and eccentric shaft assemblies (which were all matched to their particular valve - if you mix them up you're in the shite!). The long camchain looks like trouble but it's okay as long as the tensioner's regularly set and the proper rivet link's used after the chain's been split.
A contributory cause to dropped valves is the rather vague gearchange action, worse than the earlier one, as its five speed box (rather than four) is more finicky. Budget on buying new selectors if there are a lot of false neutrals. It's a lot cheaper in the long run than missing a gearchange and sending the engine to 13000 revs. By the way, it's possible to get away with this a couple of times without realising that it's stressed the torsion bar valve springs...
If there's a tapping or pinging noise from the cylinder head, walk away from the deal - the bike's a few miles off dropping its valves! As the CB250K1's basically a scaled down version of the original 450 engine (with a SOHC head) it's not that surprising that it shares the same bottom end faults.
Look for oil leaks from the clutch pushrod area and whilst doing that check to see if the chain has snapped (evidence being Plastic Metal or cracks in the crankcases). The main bearings, crankshaft, gear primary drive and even the clutch are all tough. The small-end bearings, which are machined into the one-piece con-rods, are the first sign of weakness; and very expensive to repair. A contributory cause to piston and hence small-end wear may be a loose sleeve in the cylinder. In good condition these are strong engines that can be caned despite their age.
If the chassis is a touch odd, being both short and top heavy, the tubular frame itself is tough enough to take the odd bashing from the tarmac and the cycle parts are on the hefty side. There's plenty of feedback from the road, complementing the raw feel of the motor (which should smooth out after 6500 revs). With Avon tyres and Girling shocks it can be flung around as well as most modern mounts, once the top heavy feel has been assimilated.
In this instance it's much better to go for a front disc brake. The earlier TLS drum was good for its day but ain't up to modern road speeds when fade rules. Anyway, shoes are hard to find and the casting's getting close to that time in its life when alloy fatigue sets in. A modern front end's also worth paying a bit extra for.
The overwhelming impression of riding the CB450 fast, like in the Black Bomber version, is one of fun. As the power comes in hard the motor smooths out and the exhaust howls away, it feels more Italian than Japanese...on the overrun the bike has a spine chilling gurgle that few motors can match.
It's almost impossible to make the bike run well with non-standard exhausts - they either work below or above 6500rpm, not both. The C-G 2-1 used to make a fantastic bellow but needed the choke punched on for slow speed work!
The things to look for on a CB450 are: easy starting; lack of fumes out of the engine breather; an engine that ticks over smoothly at 850 revs with an astonishingly quiet top end (give it a few minutes to warm up, though); a strong power punch at 6500 revs; lack of oil leaks especially around the cylinder head gasket; and a reasonable gearchange. If the engine's sound, buy it; the chassis can be sorted cheaply via the breakers.
Yamaha XS500
Another grouchy old vertical twin with an evil reputation but there are a few out there that have survived the ministration of speed maniacs. The later model (D or E) sorted out the heavier of the engineering problems. Some religious maintenance sessions and a light if tender hand on the spanners overcomes the way the engine alloy tends to rot (allowing threads to strip).
I actually had one of the spark plugs pop out of its thread as I was riding along. As a 250cc single it's a complete waste of time but we puffed home with oil and fuel pouring forth from the empty spark plug hole. The XS has a complex DOHC, eight valve top end which doesn't easily come apart, or rather it can be knocked apart but getting it back together properly's the big hassle. I've never known an engine on which so many threads stripped!
At this kind of age they are finicky in several areas. Both the camchain and balancer tensioning needs to be done every 500 miles, as does the oil change. And the carburation's very susceptible to rotted silencers or clogged airfilters, becoming full of flat spots. Even worse, is non-standard stuff, a 2-1 exhaust merely a way of burning holes in the two pistons.
The carbs also rot. If you can afford it, but a new set - you'll be amazed at the transformation it makes. If not strip and clean every year. You may well find an XS500 that runs very rough, has some flat spots and idles between 1000 and 2000 revs. This may just be shot carbs or, if you're lucky, carbs that haven't been balanced for a long time. On the other hand, it may be a naff tensioner system.
The good points are an excellent chassis (inspired by Yamaha's stroker range which was doing well on the track) and plenty of power and torque - as it was only a 500 with the pistons rising and falling alternatively the balancer didn't have to work too hard and thus didn't absorb too much power. If only they'd used gear instead of chain drive.
The XS500's good for a ton-ten, maybe a little more when all the elements come together. Both stability and cornering are way ahead of other seventies fare; as good as most eighties machines. Hard to believe, I know, with a machine of such a bad reputation, but on the pace it fair sings along, revealing hidden talents.
It may just have been a question of manufacturing tolerances. When all the tolerances went the right way a great machine emerged. When they didn't it turned into an old barge. This is just my theory but it ties in with the complexity of the engine and the way many of these bikes broke down rapidly. Those still left on the road have to be, by a process of natural selection, the good ones.
As the last model was made in 1979, many of them have come to the end of their useful life - it's possible to run them to as much as 75000 miles, although most need an excess of tender loving care by 40,000 miles. The engines announce their demise quite loudly with rattles, pinging and knocks. You have to be a first timer to buy a bad one by mistake, as they also vibrate and have all the acceleration of an NHS wheelchair (if there's still such a thing).
The world being a harsh, unfair kind of place, there's no way I'd recommend paying more than £500, however nice and well looked after it might appear - the potential downside is just too great.
Kawasaki GPz305
The GPz305's a modern incarnation of the sixties Honda OHC twin, that in turn inspired the XS500. They are light, fast to the ton, as chuckable as anything else on the road if a little edgy flat out, and they can be made reliable.
The GPz has a bit of reputation for ruining its valves and rockers as well as blowing its main bearings; more likely on early models than later ones. The key, as always with this type of twin, is regular oil changes and letting the engine idle for a few minutes from cold so the oil has a chance to circulate. Not foolproof, though, as riding along in the red for hours on end does stress what's after all just a small, aircooled four stroke twin.
It's dead easy to have loads of fun at speed on the little Kawasaki. The motor just needs to be wound up on the throttle and worked through the gearbox. The chassis becomes an extension of the human body, seems to just need a bit of mental rather than physical effort to flick through the bends. Even the vibration (there being no balancer) smooths out between 6000 and 10,000rpm. When it's running well it's a jewel of a motorcycle.
They do turn bad, sometimes in just a few hundred miles, when the sheer stress of it all becomes too much. A new or rebuilt engine might go for 25 to 35000 miles before giving trouble - that's five years riding for some people - but top ends have been known to go off in less than 15000 miles. Never mind, there are loads of the damn things in breakers for the taking.
A few tips that may let you pick up a bargain. Poor running and starting may be nothing more than dying spark plugs - they do go quickly, as little as a couple of thousand miles. A clattering camchain can be just a sticking tensioner. Poor handling's almost certainly shot Uni-trak bearings, they need greasing every year.
If you want to cruise at more than 90mph, especially two-up, forget the GPz, it just ain't up to it but as back road scratcher it's damn near perfect. Because of the engine frailty it's best to pay £750 or even £1000 rather than £500, although the early ones are available at that price.
Honda CB550
Both the CB500 and 400 fours are other natural options but the classic mob have elevated prices to the point where the power per buck doesn't make much sense. Enter the CB550, which shares the same engine design as the smaller fours and has the kind of soggy suspension (if not image) that defines it as a tourer.
By 1975 Honda had managed to sort out the chassis dynamics of their smaller fours. A quick and cheap work over of the CB's suspension allows a quite impressive handler to emerge. It's a small, compact and light motorcycle that can be hustled with much greater ease than, say, an early CB750. Making up in handling finesse what it lacks in outright power.
To be honest, even with silencer and filter mods, the CB never really storms up the rev range, something like a CB450 twin making it look like an old sow. They make 50hp and do 110mph, but arriving there is rather like getting into a virgin's knickers. Great subtlety and cunning needed. Similarly, cruising at 90mph is possible but a very busy affair; 80mph feels much more natural.
Probably by accident rather than clever design, the CB550 had a slick gearchange to aid and abet tearing up the rev range - an example with a loose, noisy feel and lots of false neutrals equals a very high mileage. The camchain's less prone than many Hondas' to quick demise, maybe 30 to 40,000 miles. The engine's simple to work on and repays 1000 mile services with unusual fidelity.
By this time many a model's suffering electrical rot - quite literally the insulation rots off, unfurls to let the wires short out on each other or the metalwork. This can take out the rectifier or even set the whole bike alight, an amusing sight if you're not actually on the saddle when she goes. Other signs are cutting out in the wet (which also comes from the coils or HT leads breaking down) and blowing bulbs. A charred fuse-box is another useful indicator.
I wouldn't expect to see any running original exhausts, nor even the front disc which at best was a nasty piece of work. Time corrodes the caliper until it can't be disassembled without destroying it and I know one guy who had his front disc crack up on him. Seemed pretty hilarious to me, but then I wasn't thrown off!
Really nice, low mileage ones might fetch close to a grand, but usually five hundred notes buys a sensibly modded CB with stock engine internals (big-bore kits, high-lift cams, etc turn them very fragile), upgraded suspension and brakes, and reasonable cosmetics. If you must, they can be turned classic with a black paint job and the odd bit of pin-striping.
Suzuki GT500
Of all the stokers the GT500 has a reputation for toughness that even eclipses Honda's fours. A vertical twin that has its roots in the sixties T500 which in turn spawned the T250, an old version of the GT250 discussed elsewhere. Part of the 500's toughness comes from its simplicity (no reeds, wild porting or exhaust valves), the rest from a mild state of tune that doesn't rely on revs for kicks.
And, naturally, the bike was built to a high engineering standard that proved good, in stock tune, for 50 to 60,000 miles. The one weak spot that causes collectors no end of angst was that if the bike was stored for any length of time the crankshaft seals dried out. When the motor was started they cracked up, allowing gearbox oil to be pulled into the crankcases.
This made for tons of smoke out of the exhaust and a broken gearbox. The GT's box was very smooth and slick from new, so any bike that has a poor gearchange has probably suffered from the demise of the seals. It needs a rebuilt crank to fix the problem, which given the variable quality of mechanics isn't a good thing.
Any engine that smokes heavily but has a good gearbox (check the oil level in the box before and after the test ride) may just be suffering from an ill-adjusted oil pump. Set up correctly and run on modern stroker oil, there should be only the lightest of mists. They are that fine a piece of engineering.
The most likely cause of excess pollutants is worn rings. They are lightly stressed by the engine but sometimes neglect of the ignition timing causes the engine to run hot. It can survive that kind of abuse for quite a long time but something will eventually give, and it's usually the rings.
One sign of a good engine's liquid smoothness right up to 8000 revs. Despite the lack of the sophistication of a balancer, Suzuki had perfected the dynamics of the motor and the way it interacted with the chassis. 50,000 miles does make it harsher but if you find your feet shook off the pegs, chances are the bore or crank bearings are about to go.
It's this surprising smoothness that first impresses. Although the engine can work hard it doesn't have the kind of power band of which legends are made. Newish suspension complements it, but by now new shocks and upgraded forks will have been fitted, unless the machine belongs to a collector or some other kind of low life.
This is one bike that's definitely for riding reasonably fast. 110mph on the clock, no problem, and 90mph cruising for a couple of hours. Fuel stays reasonable at 50mpg. The frame handles most abuse thrown at it, having none of the hidden horrors of, say, a Kawasaki H1. Compared to a similar era CB450, the GT's as fast and a lot less brutal getting there.
Surprisingly, there are still many excellent examples out there, more or less standard, with plenty of life left in them. Avoid any tuned bikes, even those with just spannies and jet-kits, this really was one motorcycle that the manufacturer had set up perfectly, given the technology of the day and the speed constraints on UK roads.
If you want to go faster, experience a similar bike but one with a heavier power output and harsher character, go for the earlier T500. Another highly competent and tough stroker twin, which can stomp on the later GT500 and has even better classical looks.
Alas, the T500 had much more appeal to the kind of rider who revelled in the RD style of stroker experience and many ended up thrashed to death by 40,000 miles. There are not an excess of good ones out there at bargain prices. Also, with over 25 years of abuse alloy rot and fatigue rules, making things like the drum brakes, not to mention engine bolts, a touch dubious.
The T500 also had weak suspension that brought in some high speed weaves, if not wobbles, and didn't, even on improved suspension, offer the same kind of reassuring stability of the GT. Many frames ended up slightly bent after the excesses of mad youths, adding to the high speed carnage.
Whilst £500 might buy a reasonable GT500, although £750's nearer the mark for the quality end of the market, as much as a grand's needed for the T500, such is its reputation amongst the classic brigade. I'd happily pay £500 for a GT but not twice that for the T500. I know one guy who bought what he thought was a pristine T500 for £1250 and found out to his cost that it was a rolling death-trap - bent, cut and welded frame; cracks in the drums and an engine with alloy-welded cracks in the crankcases. A quick way to an early grave if he tried to speed on the old heap. There are a lot of rip-offs in this market so you need to know what you're doing and not get carried away by enthusiasm.
Yamaha XJ550
Enthusiasm, at the time, was largely lacking for the XJ550. Kawasaki's were fast, Suzuki's were tough, Honda's were, er, Hondas...and Yamaha fours had solid virtues but lacked the inspired touch. The 550 proved the toughest of the XJ series and wasn't so slow that it can't be included here.
There were shades of the Superdream's built-in obsolescence. One thing to know about this engine's that if 1000 mile oil changes were neglected it could be out of business in 25000 miles. Some did over 70,000 miles in sedate hands but that's as rare as a CB250N lasting a similar mileage. As well as engine demise (usually in the top end, primary drive and gearbox areas), the chassis rotted away merrily.
This rapid demise encouraged some enthusiastic if not desperate renovations, which if they included the chassis bearings and suspension was all to the good. With 4-1 exhaust and K & N filter, there was enough power to do 120mph and hard use of the gearbox and throttle put most other bikes available for the same money to shame.
The XJ never impresses with its sophistication, but the basics are near enough right for the elements to come together on the road. Some owners fell in love with them and there are examples that have sensible mods that add to the experience. Others went the way of rats, ending up with little that could be salvaged.
Cosmetic condition, in this case, is a useful indication of the level of abuse and the likelihood of the engine lasting for more than a few days. If it looks good then the only other likely hidden nasty is the electrics. As nefarious as a Soho hooker and about as sophisticated. Both rotting wiring and a dying rectifier can play havoc with the bike's running.
Also, it only takes one slight degradation in any of the ignition circuit components, switches or wiring for the bike to start cutting out. This might be a good bargaining point other than that shagged piston rings, worn out carbs or burnt out valves also cause similar symptoms. If there's a lot of hassle involved in finding a good example, then for the money (£500 to £750) there's little else that can go so fast. There's always the option of force-fitting an XJ600 mill.
Honda XBR500
It's a lot easier to buy some fast kicks for a thousand notes rather than half that. The XBR comes with an excellent chassis and generally reliable motor. Also available as the GB500, same engine and frame with even more retro clothes. Don't try any tuning tricks on the OHC motor, it's tough but not that tough!
The power output ain't mind blowing but the single cylinder layout means there's a lot of torque backing up the speed. I've done a couple of hours at the ton without going crazy. The bike will churn along imperious to hills or wind. The somewhat radical riding position making a lot of sense, which is more than can be said in town. There, my wrists were in agony and my back complained with electric spasms.
Handling, even on worn OE suspension, is close to excellent. Though some might find it a tad hard going in the bends, I will favour stability over twitchiness any day. There's nothing more disturbing than being on a bike that at any moment might turn in a suicidal speed wobble.
The only weak spot in the chassis was the front disc, which could go wafer thin before cracking up and, of course, the calipers do rot in British winters. The only cheap solution's to hit the breakers for a good used one (discs off other models can be adapted).
Like many a big single with a balancer and a light flywheel, the engine can cut out at low revs when waiting at junctions. The electric start makes this less of a hassle than in days of old, but may explain why starters burn out before any other engine hassles turn up.
For an engine that has its pedigree in the awful FT500, the XBR turned out to be made of sterling stuff. Much better, in fact, than most of those old British thumpers from which great fantasies are wrought. If you think that the Gold Star ain't any faster and recall all the hassles that was involved in starting and riding such a terrible old heap, then a little bit of stalling in traffic ain't much to put up with.
The good news is that the XBR engine will run to 40,000 miles, maybe 50,000, without any major traumas. The bad news is that major components start failing after that, first the valvegear, then the piston and balancer, and fatally the bottom end. Paying big money for one with 60k on the clock's like throwing money into a bottomless pit. I wouldn't touch anything which had done more than 25000 miles unless factoring in the cost of another engine or full rebuild.
Bearing that in mind, it's definitely better to go for the decent, low mileage stuff at around the grand than become involved with some old hack. There are plenty of neat ones out there as many were bought by would-be collectors who are now off-loading them because of the cheap grey import GB500's devaluing their possible classic status.
Yamaha XS650
Unlike the XBR, the XS650's engine lasts almost for ever, even if by 50,000 miles it's making an excess of rattles. Probably because they can run for years without even the valves being set. The vertical twin engine does vibrate above 7000 revs, but the thrum isn't any more intrusive than on the XBR and, anyway, most of the power has disappeared at those heady revs.
The OHC engine's massively over-built, lacks any of the complexities of modern twins, such as balancers, and can push the bike right around the clock. Camchains around 60k and starter motors that can go awry by wrecking the crankshaft at as little as 30k, are the two major problem areas to watch out for.
Oh, and there's the handling. The XS650 had sorted the more blatant traumas of the earlier XS-2, but still hid within it chassis the possibility of massive speed wobbles. One moment trundling along at a stable 90, 100mph, the next going into a real tank-slapper with the bars twitching furiously from lock to lock. You need rather a wide road to survive.
This happens only a couple of times a year but it's so frightening that most people rush out to buy a steering damper. The other alternative's to loosen the death-grip on the bars without backing off the throttle. What normally happens is that the rider tries to fight back against the wobble, which just increases its amplitude. By loosening off the grip the wobble has a chance to die down. This doesn't work on every bike but it does on the XS650.
The weird thing about the Yam's that for most of the time it has an inspiring, well balanced feel that encourages taking the machine to the limit. And for most of the time it can be scooted along with some elan despite weighing nearly 500lbs.
The chassis is tough, well finished, but non-standard components including exhausts (OE silencers rot rapidly) are quite quickly destroyed by the primary vibes that get through the chassis. Top speed's only 110mph but the sheer durability of the plot compensates for that.
As well as the straight XS650 there were a couple of custom versions that don't really fit the bill for speeding but are handy as a source of spares. The earlier XS-2's more interesting. The engine's just as tough but more powerful, good for 120mph, though that last 10mph does bring in some eyeball popping vibration - nothing a Bonnie addict couldn't take. XS-2's have become a bit rare in the UK but some grey imports from the States are getting through.
The big problem with the XS-2's the chassis. The frame geometry, simply, ain't right. If everything's set up perfectly then it's not such a bad ride, especially as its 30lbs lighter than the XS. However, if just one component goes off, one set of chassis bearings wear too heavily, then it's rocking horse time.
As this bike's being considered in terms of speed then this is bad news. There is a solution of sorts. Upgrade the whole front end with something modern (I've heard the GPz750's front end works marvels) and stick an alloy swinging arm with Hagon shocks out back. The geometry's still crap but the decent suspension keeps the bike under control for the majority of the time.
Grinding through bends, hitting bumps and snapping the throttle shut, for instance, even with the modified suspension, can still have the bike wobbling all over the road in full out death-mode. Throw in the same speed wobbles as on the XS650 to end up with a gibbering, crazed rider.
To make things even more interesting there are big bore kits, as much as 840cc! The torque's stunning but the vibes can be vile. Reliability depends on how well the rebuild's done, with so much low down torque the engine can run much taller gearing and cruise at lower revs; therefore, has the potential for longevity. But many of them destroyed themselves over less than 20,000 miles.
The brakes on all models are crap. If they've been dumped for something more modern consider yourself lucky. Wet weather lag, pads that fall out when down to the metal and a disturbing lack of feedback. An easy way to die young.
Because of the poor state of the chassis and durability of the engine it's worth considering bikes at the lower end of the market with the potential for a suspension and brake upgrade. That means around £650 for one with a really good engine. A grand will buy either an XS650 or XS-2 with sensible mods and lots of life left.
Suzuki GS550
The GS550's the safest way of going fast. Not only is the tough engine unlikely to seize up and cause a fight with the tarmac, but the chassis geometry instils the bike with fantastic stability. It never comes close to a speed wobble, doesn't even weave unless the suspension and bearings are really shot. Backing off the throttle in corners tightens up the line without inducing any back end traumas.
The only blight from the chassis occurs when the front discs are used with the GS banked into a slow speed turn. Then the bike flips back up to the vertical with a mind blowing violence that almost knocks the rider out of the saddle. The average 125 graduate will fall off. Avoidance takes merely a reliance on the back brake in such situations. Bear this in mind when going for a test ride.
The GS550 range, especially the later models and the Katana, were heavy beasts. The cast alloy wheels alone must've weighed more than a bag full of spare engines. This heaviness was partly responsible for the slow steering but because it was so stable excessive muscle won the fight in the bends without much chance of a trip down the tarmac. Heaving the Suzuki through the curves soon becomes second nature.
Most of this sweet handling results from a well braced tubular steel frame whose geometry was not dissimilar to an old Norton twin, though the 100lbs extra weight lost the latter bike's easy steering.
The bearings were long-lived and even the suspension didn't go off with age and mileage, although the back end benefited from an alloy swinging arm and set of newish Koni shocks. Forks, in reasonable shape, absorbed most of the bumps, helped along by a good a riding position.
The disc brakes had power but not much by way of feel, becoming a bit touchy in the wet when the lag had the rider teetering on the brink of a nervous breakdown. Later models even had a rear disc, which given the need for lots of tender loving care on the quick wear chain, was soon covered in grit and could happily corrode up solid. Running on the earlier drum/disc wire wheels isn't such a bad idea.
The 550cc four cylinder engine only develops 54 horses, so is mildly tuned by Japanese standards. The hefty build quality would suit a 750cc (and, indeed, there are big bore kits that take it out to as much as 740cc - try to avoid as reliability suffers), so it's not surprising that a lot of them would run around the clock even under a regime of neglect.
Although acceleration might not be too thrilling, it's always smooth and can hold on to high cruising speeds without being deflected from its destination by barriers such as steep hills and gale force winds. More go can be extracted with a Motad, K & N's and a jet-kit; an almost mandatory excursion into aural adventures because the stock 4-2's rust rapidly until the end-caps fall off. A pair of universal mega's on the ends of the existing downpipes works well with the standard carburation and air-filter.
If your idea of speed's rapid cruising then the GS is near ideal. A useful tip's to run it on a larger gearbox sprocket, the taller gearing making for a much more relaxed 100mph gait and improving the economy by as much as 10mpg. The gearbox remains slick even at high mileages, although the linkages on the Katana's rear-sets wear at the joints when their protective covers perish. Any GS with a box full of false neutrals has probably done over 100,000 miles.
Comfort on the stock bike's quite reasonable but the Katana has a seat that turns concrete and the edges of its huge petrol tank chaffs the rider's inner thighs. The Kat's a beautiful looking brute but as a long distance cruiser has severe limitations. Having said that, I did a 300 mile daily commute on one for a couple of weeks; keeping the speedo between 100 and 110mph kept my mind off the pain. I'd probably go for the Katana's looks in favour of the standard model's practicality.
The whole GS series was afflicted with one major hassle - naff electrics. All kind of theories are posed as to the cause but by now most bikes will be running on a rewound alternator, Superdream rectifier/regulator and a rewired circuit. Once the rectifier goes the only thing to do is disconnect it and charge the battery up every night - it'll run for about 150 miles on a fully charged battery if neither lights nor horn are used. An alternative to the Superdream rectifier's to use a car rectifier and regulator; a mere tenner the pair from most auto spares shops. But the wiring's quite hard to figure out.
Because the engines are so tough some bikes were run right into the ground, totally neglected until the chassis rotted away. Amazing tales are told about the indestructible nature of the GS550, running them for 20,000 miles without even an oil change not uncommon. Other people were inspired to refurbish the chassis, lose some mass and upgrade the brakes. Others were left stock but kept in a very nice condition.
Thus the used market's somewhat confused but if you persist it's possible to find bikes with only 20 to 30,000 miles on the clock that have loads of life left, available for around a thousand notes. Given the toughness of the engine another option's to go the rat route by doing a complete chassis refurbishment.
Kawasaki 500 H1
From the sublime to the ridiculous. Kawasaki's infamous triple gives a tremendous kick in the guts thanks to its wild, wild stroker triple engine. The chassis seemed to be deliberately engineered so that the front wheel spent most of the time a yard or two off the tarmac. This combination proved exhilarating, amusing and so damn frightening that diapers should've been a compulsory accessory.
Even with both wheels firmly on the tarmac, the handling was savagely strange and about as predictable as an amphetamine addict locked in a chemists. Sometimes even minor bumps threw the H1 into a massive speed wobble for no apparent reason. Another trick was to throw the bike into a fit if the throttle was slammed shut in corners - it'd lurch over to the other side of the road to play chicken with oncoming cars or hedges. Coming out of bends hard on the throttle was okay until the front wheel went light and the bars twitched from side to side.
There was no easy cure for the madness, although the brave held on for dear life and fought with the chassis. Some poor souls actually took them on the race track, adding about 50lbs of frame bracing to very little avail. Many suspension mods were touted but they never really whipped the beast into line.
The engine was very powerful, even today the way the kick comes in startles - it's never a boring bike to ride. Expect minimal engine life. Spark plugs burn out in hundreds rather than thousands of miles. Almost as much oil's needed as petrol, which at 25mpg was pretty mind boggling on its own. The engine rattles like a pack of football supporters after a winning goal.
A good engine, with 500 mile services, might just manage 15000 miles before needing a complete rebuild. Quite impressive, given that there's always a feeling of self-immolation and some frenzied vibration that reminded me, for some reason, of a rather ill Tiger Cub.
The later KH500 tamed the madness to an extent but most used examples have been stripped down and tuned up, making them just as raw and raunchy. As a sole bike, forget it, but as a tool for adrenaline junkies and speed maniacs the excess of kicks is almost compulsive. At £1250 for something good it's not a bargain but in the bland nineties it's probably too good to miss.
Honda CBX550
The CBX's another potentially troublesome machine that can go fast enough to provide some high speed kicks. They are the cheapest of the hot 550's simply because they have an abysmal camchain tensioner. It can go pop at any moment, ruining the potential for long distance riding. If you ride for any length of time with the camchain rattling the top end dies a dismal death. With DOHC's and 16 valves it's a rather complex job to sort by the roadside.
Most bikes ran to about 12,000 miles on the original components but replacement tensioners and camchains went for less than that. There are some bodged tensioners that will just about get you out of the vendor's street, so a heavy test ride's needed. Later models had better tensioners, would maybe go for 15 to 20,000 miles. These can be retro-fitted to earlier models but it's still a dubious trip. DIY replacement's possible to keep the costs down but I know one guy who got the valve timing out by a tooth - he ended up with about 200lbs worth of paperweights.
The really sad thing's that the rest of the bike is so good. 120mph, stable and light handling, and reasonable running costs. Throw in a cheap purchase price because of the reliability problems and it becomes an interesting if potentially vexing proposition.
It's quite important to upgrade the front end because the enclosed discs become nasty with age, say 30,000 miles. The excessive weight of the front wheel should've made for some high speed wobbles but the geometry and strength of the tubular frame does a good job of keeping the bike in line. The Pro-Link back end's typical of the breed, needing a yearly strip and grease. If that ain't done the whole lot starts grinding away at all the joints and bearings.
I rode around on a 60,000 miler for a while, was continually surprised by the way it could be hustled even on worn out tyres and soggy suspension. It weaved at speed and felt a bit loose but even whacking over some big bumps didn't let the handlebars wobble. Never came close to the quick death routines of the H1.
Wet weather wasn't so much fun, the bald tyres bringing in some large slides that had me fighting the 400lbs of metal all the way. Most bikes go the same way on slicks, so I shouldn't really complain, although the CBX was in such a decayed state that it didn't seem worth spending out a hundred notes on a new set of tyres.
A lot of bikes on the used market have gone the same way. People become pissed off with the motors and abuse them something rotten. There's the odd one that's been used for mild touring, which might be worth a look but it still suffers from the camchain blues. Certainly, a thousand notes should buy a very nice one; £500 to £750 a good runner in need of cosmetic attention. Always have a spare camchain and tensioner to hand.
Kawasaki Z650
Big, bouncy and sometimes brutal, the early Z650 was a cycle that many British bike fanatics felt at home upon. Neither smooth nor remote, its 65 horses always had a reassuring amount of blood and guts. The kind of motorcycle that can be ridden fast without looking at the clocks all the time.
Perhaps embarrassed by the reputation of the H1 and Z1 both, Kawasaki went to some lengths to make the 480lb straight four handle. Success wasn't total but it at least was wholly predictable in its limits - mostly down to its weight and slow steering. And, uprated forks with heavier springs, a set of aftermarket shocks and upgraded chassis bearings, worked wonders. It was still possible, though, to hurtle into bends too fast and end up on the wrong side of the road all out of shape...it takes a while to know its ways but there are some guys out there who can ride `em really hard; scaring the shit out of the plastic replica brigade.
Most bikes have had the chassis modified, some with the useful addition of an alloy swinging arm. The engine was tough stock, good for 125mph on the clock. A 4-1 exhaust and modified air-filter might add 5mph to that, it certainly made for a marvellous exhaust bellow and induction roar. The former a must if you're going to ride hard on UK roads, about the only effective way of waking up sleepy cagers.
The engine's a tough nut to crack, runs to as much as a 100,000 miles. By then the hyvoid primary chain's thrashing around furiously and the top end's rattling like there's no tomorrow. The rest of the bike can be more problematic - the electrics rot leaving some bikes burnt out; the disc brakes die a death around 30,000 miles; the petrol tank rusts through around 60,000 miles when most of the paint goes off.
In the overall scheme of things these are, if you know about them, minor hassles that can be fixed along the way. Don't be put off by high mileage examples sporting much modified chassis. Assess them by the way they make the bike easier or harder to enjoy. Although there are collectors hovering like dirty old men in Piccadilly, the Z650 hasn't yet been swamped under the burden of becoming a classic. It's too good a bike to ride to keep in a f..king museum.
£1000 still buys an interesting example. Something with sensible mods, 40-50,000 miles on the clock and loads of riding left in it. £1500 buys something with less than 20,000 miles under its wheels and a fairly standard chassis.
Yamaha XJ750
It so happens that for six months I bopped around on an XJ750. Rode the balls off the bike, did absolutely no maintenance and even skated around greasy London roads on near bald tyres. I didn't fall off, the engine didn't break and I wasn't arrested by the cops on charges of moral decay or even riding around on a dangerous, decaying heap that had last seen an MOT five years previously.
The XJ doesn't look tough or as if it's doing 150mph standing still, gets an easy time from the cops who assume the rider's an old codger out for a mild ride. The handling's weird, the final drive rumbling away and the bar's sometimes going into a shaking fit. The worn out suspension didn't help. None of that stopped me putting 130mph on the clock, laid flat out on the tank, helped along by the ace-bars a previous owner had fitted. It was man against machine time, but the XJ was sufficiently well sorted for me to win.
Maybe I was just lucky. But there are plenty of examples that have run to 60,000 miles and stayed more or less in one piece. The engine can be tough or turn out a pile of old shite - all down to regular oil changes and the odd maintenance session. Not as tough as either the GS or GPz series but better than many a Honda four. Worth listening carefully (with the old screwdriver routine) for any knocks as the main bearings can be short-lived if regular oil changes are neglected.
The 750's relatively rare compared to both the 650 and 900 versions but goes better than the former and doesn't have the sometimes appalling road manners of the latter. Consider the 650 as a viable alternative, it's a bit tougher but the shaft drive makes it relatively heavy for the power and most good 550's can burn it off. More than most, the 650 was a favourite amongst tourers and often led a very easy life. Which was just as well as it had similar mechanical problems to the 750 model.
I recently had a blast on a well sorted XJ650. All the right mods and a peach of an engine that really sang along despite having 32000 miles on the clock. It was more hard work on the throttle and gearbox than the outright flow of power that made her shift, but she ran hard as a thoroughbred horse on a winning streak. Had the suspension been standard I would've probably fallen off - but S & W shocks and a nearly new XJ900 front end gave sweet, neutral handling that not even the churning shaft drive could disturb.
A grand buys a good example of either but when used for speed they do need very regular oil and maintenance sessions. Neglect and high revs just leads to a crankcase full of engine bits. The bikes don't have much of a reputation but there are some well sorted examples out there.
Suzuki GS650M
The GS650 engine was mild and stodgy in GT form but the Katana version was tuned to 73 horses. Whilst this was in line with many 750's, so was the mass at around 500lbs and the handling was less assured thanks to the ruminations of the shaft drive. Given the way that other GS models tore through their chains this was something worth living with, as the worst machinations only turned up when the going got vicious.
The larger engine was less hardy than the 550 version, though it was still a heavy job to ruin the bottom end (with the possible exception of the clutch due to savage retribution from the shaft drive when in wheelie mode). Much more likely to take out either the pistons, camchain, valves or cams under heavy throttle use and after 35000 miles.
The most likely sign of cack-handed rebuilds found in bodges to the bolts holding in the exhausts headers, which have an unpleasant habit of snapping off. Check these even to the extent of going over them with a spanner; they were often glued back in! Also, look for oil leaks around the cylinder head (but a slight smear from the head gasket's par for the course).
An engine in good nick should have an arm wrenching urge between 6500 and 9500rpm; run smoothly and sedately at lower revs. Carb rot can turn running very malignant, often occurs after fifty thou and may even necessitate replacement of all four carbs. In good nick, they don't need much attention if the clutch rattle around 1200 revs doesn't cause any worry. If the engine rattles at higher revs, most likely the automatic camchain tensioner's shagged (or it may just be stuck). Mildly used examples can run their camchains and tensioners to as much as 50,000 miles.
Such machines tend to be rare, the appearance and character tending to attract owners with itchy right wrists and something to prove...Or it may just be that the godawful shape of the tank/saddle interface makes everyone who spends more than a few minutes aboard thrash to death the engine in revenge.
Whatever, out there in the marketplace there's some fantastic and dangerous dross. The need to speed combined with excessive mass and dodgy perambulations at the edge also means that some of these bikes feature a bent frame, which turns the solid handling as amusing as riding an NSU Quickly on flat tyres.
Certainly, finding the fabled one owner, low miler for around a grand would prove impossible. That kind of money will buy something with forty to sixty thou on the clock, with a fifty-fifty chance of ending up with a usable bike or an old dog that will needs loads of work and money to fix.
Honda CB750F
Another old whore, often more trouble than it's worth, the CB750F1/2 was the end of the line for Honda's original OHC four that took the market by storm back in the late sixties. In 1969 the massive weight and width was acceptable in exchange for the smoothness and reliability, however fundamentally unsuited was the across the frame four as a motorcycle engine (both in terms of carrying too much weight too high and in its lack of torque and frugality).
Thus progress in 1975, with the introduction of the F1, was not too startling, merely a couple more horses, a slightly more sophisticated feel and the taming of the more suicidal wobbles that resulted when the K1 was ridden hard...
At least for the first 10,000 miles, after which the suspension went off, the sophistication did a runner and the wobbles came back. Laugh, then, at any bike which doesn't have firmed up suspension, flat bars and rear-sets. Or maybe not, for something with the original fare's unlikely to have been ridden hard!
Alas, even with those mods the F1/2 didn't quite excel as a speedster because the motor lacked the sterling reliability of the original, with a list of possible nastiness that ran the length and breath of the motor - from a transmission that could break up to a crankshaft that could play knock-knock, though, more likely, was piston ring or camchain breakage.
This isn't to say that every motor made was a pile of crap, just that enough of them had problems to keep a cynical mind, beady eye and acute ear when viewing machines; indeed, there are some out there that ran to over 75000 miles with nothing more than regular maintenance, usually under a mild hand and even temperament.
Another factor to bear in mind, these models were particularly susceptible to cutting out in the wet, something that in chronic cases not even the wholesale replacement of the electrical and ignition system could cure. True, almost any Honda four of this era could similarly be afflicted and there are many bodges (usually involving black gunge) that can help, but a minority of F1/2's are quite beyond help. A sure sign of such a bike is a large number of owners in a short time.
The frame being solid enough, and age turning the rest of the chassis loose, sensible modifications should be welcomed. Turning the CB into a reasonable sportster, rideable up to 120mph, ain't that difficult, as frame geometry and weight distribution were both reasonable, though nothing's ever going to change the fact that it's one heavy, wide mother.
Beware of petrol tanks rusting through without warning; an incidental hassle being carbs that clog up from the resultant debris - incidentally, many sixties Hondas were better finished! The best part about this Honda's the price, a grand buying a really nice one, half that purchasing a rat still some distance from a sojourn in hell. Engine quality being so variable as to make the mileage on the clock meaningless, look instead for a quiet, oil tight mill with a slick(ish) gearbox.
Kawasaki GT750
74hp, 125mph and 500lbs means that the GT's in the speed game despte its conservative styling, shaft drive and slightly squeamish suspension. The GT's definition as a tourer does mean that many lead a respectable life, although at the other end of the scale, many were bodged through a 100,000 miles of despatching. These bikes are easily recognizable by decayed cosmetics and rough motors, although poor running below 3000 revs is normal on pre `92 bikes.
The GT's a solid enough bike, with most of its handling foibles ironed out by a decent pair of shocks and tyres...it's still slow turning but an excess of muscle overcomes any reluctance to corner even if the presence of the shaft drive makes an apprenticeship in smooth riding on a seventies BMW's quite useful.
It takes some quite extreme abuse to bend the frame, not so the forks which tend towards going plastic with age. Given that the calipers on any bike old enough to go for a grand are going to be dead meat, a later front end's a useful if not mandatory aid to directional stability.
Comfort's quite reasonable on a stock bike; it's not really worth putting up with clip-ons for the marginal benefit of improved top end performance - and it looks pretty daft on a machine with the GT's appearance. Old GT's do corrode badly, especially on the wheels and inside the petrol tank. Worth giving the latter a few hard taps; better to annoy the vendor than suffer a groin full of petrol, the resulting rash rather embarrassing. Aged front wheels are a dubious proposition - I know of two that've cracked up! Okay, it took over 75000 miles and a couple of minor accidents to destroy them, but still worth bearing in mind on a bike capable of 125mph.
Funnily enough, the early models are a touch harder charging that recent examples, which have more midrange grunt. Swings and roundabouts. Properly set up, the GT's quite happy to cruise at the ton, with a little power in hand for desperate escape manoeuvres, though between 110 and 125mph performance's best described as constipated. For some reason, even a straight through 4-1 doesn't liberate any more go and the GT makes an awful racket when on cam.
Thrashed engines die in as little as 30,000 miles. Camchain, valves and pistons are most likely to die an early death. Extreme neglect of oil changes can even take out the crankshaft bearings. Not a common malaise, evident by an excess of vibes and knocking noises from the bottom end. Further carnage can be traced to a noisy primary drive and a gearbox full of false neutrals. If the worst happens there's a reasonable supply of engines and used parts in breakers.
Sudden engine demise's quite rare, a motor that sounds and runs okay is likely to last. Not so the electronic ignition, which can go down without any warning. Best to use extra rubber under the existing one and buy (and carry at all times) a good used examples (which are quite rare and thus not bargained priced).
Just as the cosmetics rot so does the electrical system; the state of one a reflection of the other. This carnage's often expanded by some wanton bodging. Anything over ten years old really needs all the wiring pulled out and replaced. The same goes for the switches, which in shorting out intermittently can cause all kinds of the electrical problems.
Early models also featured an alternator which could easily be overloaded by the addition of more powerful lights. The subsequent wrecked charging system could also take out the ignition or cause minor fires. Hmmm! This lack of build quality does show up in the pricing of early models available for much less than a grand, though if you want something with reasonable engine life £1000 to £1250 is a more reasonable target.
Suzuki GS750
The big old GS750 was not a dissimilar hustle to the GT, though being a touch more sporting and classical in nature. The GS always seemed to have a bit of a fight between its mass and chassis; even Ducati-hard suspension didn't entirely eradicate the weaves and wobbles at 120mph. The GS had a stronger, more urgent top end, felt happier the faster it went. Even the secondary vibes, more intrusive than on the GT, just seemed part of the rawness of the experience.
Those totally bored by the banalities of modern life can achieve a new sense of survival by running the GS on cheap or bald tyres. The tubular frame looks strong and well braced but either it's made from crap steel or the geometry's lacking - when something's a little worn in the chassis or the tyres are naff then it careers all over the shop with a self-destructive mind of its own.
Up to the ton, with decent suspension and tyres, it's not half bad, just needs a little effort to control. Pushed to its limits, the chassis can bite back in a big way. Especially in the wet when, regardless of the tyre and suspension permutations, the remoteness of the tarmac from the rider's never overcome. Most GS riders end up using a very mild right hand in the rain.
The GS750's also very susceptible to a misaligned rear wheel. If it's just slightly out the bike wobbles all over the place. With rapid chain wear this is enough of a pain to make it worth buying an alloy swinging arm with eccentric adjusters. If the back wheel's set up to perfection and the bike still feels edgy, then there's probably a slight kink in the frame. At this kind of age it's not a good idea to have the tubular frame straightened.
An aside. One of my mates bought a GS750 with a mono-shock rear end conversion and tuned motor good for 135mph. He reckoned it was the business, though to my eyes it wobbled all over the place down country lanes. No-one tried to overtake him because he looked so suicidal. The nemesis came after six months when the shock's lugs sheared off at about 70mph! I've never heard such a terrifying mechanical screech before or after. Nor seen a bike so thoroughly written off. The rider survived with merely a severe bruising.
It's always better to avoid the more extreme modifications to old Jap's - always invariably, even when done professionally, they haven't had the proper long term testing. On the other hand, things like wheels, brakes and suspension don't age very gracefully, are better replaced with more modern fare.
The GS750's one of those machine that attracted people who liked to make wacky mods which also had the vaguest relationship with good engineering practice. Variable build quality encouraged such antics and nice, original condition bikes are becoming both rare and expensive.
Indeed, a frighteningly large number have gone the rat bike route, more useful for making survivalists high than for speeding. Any bike with a rust encrusted frame is likely to fall apart if ridden hard - literally. The engine's raw enough to show up any serious problems with an excess of vibration, noise or smoke. The weakest spot's the clutch, which will explode under wheelie madness. High mileage needn't be that bad a deal if the general cosmetic condition's reasonable.
Classic collectors are trying to push prices high but good bikes are still available in the £1000 to £1500 range; rats for less than £500.