Tuesday 6 September 2011

Kawasaki Z400


I really wanted a Honda 400 four but could not afford one. I bought my Z400B1 in 1981 for £450, it had 11000 miles up and was in need of a new exhaust system and swinging arm bearings. When I got home I put a broom stick up each exhaust and could rattle it around. This gave the bike a great sound but gave me a headache riding it.

The first of these problems was not difficult to solve and through the ads in the motorcycle press I acquired a Dunstall 2-1 for £50. The second was not so easy, it took about at day using a hacksaw blade to cut the outer track of the roller bearing, but once done I was able to drift the other out. Replacement was easy and parts were readily available.

I was very pleased with the bike as it seemed really fast after my Honda CB250G5, the less said about which the better, and handled quite well. The engine seemed smooth due to its balance shafts and had a noticeable power surge at 7000rpm together with a change in exhaust note.

The Z engine looks neat and features pistons moving up and down together, the balancer driven by a chain. There is less vibration than on British twins and this arrangement keeps the same smooth exhaust note as on Brits as opposed to the offbeat noise made by things like GS400s where the pistons move up and down out of phase.

A single overhead cam takes care of valve control and ignition is back-to-basics points. Black boxes are all very well on newish bikes, on the older stuff they are a potential minefield; new replacements costing more than the bike is worth.

I was soon using the bike every day for commuting and at weekends. It would cruise at 80mph without strain and would do just over the ton. The most I ever saw on the speedo was 108mph. Acceleration was reasonable, few cars able to keep up. The bike could plod along just like some ancient British heap if you had a mind to take your time. Unlike more frenetic bikes, the Z did not have the kind of character that made you rev the balls off it everywhere. A typical old style vertical twin.

I used to change the oil every 2000 miles when I gave the bike a good service, which was easy as there are only two valves per cylinder and one set of points. The only expensive part was replacement of the a diaphragm - I had to replace one whilst on holiday. When these split they can cause rough running or make the cylinder affected refuse to fire altogether. If you don't know what the problem is it can create endless hours of fun trying to get the motor to run properly.

I found the engine almost indestructible and once saw the tacho needo pointing straight down, way past the 9000rpm redline when it jumped out of gear on full throttle. I expected to hear expensive engine noises when I stopped but it ticked over as normal...

I did a few long trips on the bike during the six years of ownership. I went on holiday to France with my parents who were on a Triumph 650 - the performance of the bikes was very similar, any power advantage the bigger bike had was limited by its production of primary vibes at higher revs. It was in France that I recorded my best fuel consumption of 83mpg - due to the good roads and lack of traffic. The average was usually about 60mpg.

If you ever get the chance to go to France, do so. I found most drivers courteous and traffic very light. It made a pleasant change from the south of England and its congestion.

I was a little concerned as one of the bike mags, now defunct, said that at 20,000 miles the engine would self destruct. It didn't. At 27000 miles I gave it a top end overhaul, the only thing it needed was some new piston rings, everything else was in good shape. I think I did this through boredom as the G5 had to be pulled apart every few weeks.

The first time the bike let me down was on the way home from work one night when the lights went. It was quite spectacular. All of a sudden the road turned blue, like the light from a camera flash and the bike stopped. On investigation I found that the connection to the battery had come off, causing the full output of the alternator to go into the electrical system. The very nice man from the AA took me home and after replacing nearly every bulb all was well again.

Spring '88 I did a full engine rebuild. The stripdown was easy enough, these are fairly simple engines even by British standard let alone the new watercooled jobs with an excess of valves and cams. However, I only needed to replace the main bearing shells and camchain. The cylinder bores were not worn and the piston rings were still in order. When I had the engine apart I was impressed with the engineering and the strength of the parts. The main bearing shells are the same part as the GPZ900R!

In 1988 I went to the IOM TT on the Z and it was here I felt I needed something bigger. The bike still performed the way it did when I first got it but the speed of traffic had increased to the point where 80mph was almost a minimum. It was also on the IOM that I felt its handling limitations. It was on the mountain section of the circuit with its long sweeping bends that it got into difficulties.

I was going around a right-hand bend at about 80mph when a lorry came in the opposite direction. I must have lost my nerve and backed off the throttle which caused the bike to weave nastily. I probably would have been alright if I had kept going. It was quite unnerving seeing bikes in the mirrors and then a few seconds later storming past.

It was on the IOM that the bike let me down for the second time. The problem was a bad connection from the voltage regulator to the battery. Unfortunately, I did not discover what it was until it had burnt the regulator out. However, I was able to get one in Castle Town on order - which took two days. I borrowed a friend's GPZ900R whilst waiting and the Z felt a bit like a toy afterwards.

I found that rear tyres lasted about 5000 miles and I never wore the front one out in 35000 miles. I always used a rear Dunlop K181 which gripped the road well. I replaced the front disc pads after 20,000 miles, the rear shoes were never changed. The brakes were reasonable but the front needed loads of muscle. Chains lasted between 10,000 and 15000 miles depending on how often it was cleaned.

After getting back from the IOM I still wanted a larger bike to go to race meetings. I looked through the dealers for secondhand 750s but was not successful. In the end, I bought a new Suzuki GSX550 at a good discount and got £300 in part exchange for the Z400. I was sorry to leave the bike at the shop on the 1st August 1988, but after a few miles I realised the Z400 was getting a bit long in the tooth.

I would have kept it if I had not needed the money for my new bike. I would certainly buy another one for commuting, although it has to be admitted finding a lowish mileage one would prove difficult and they are now getting very rare on the road.....but I have seen the Z since selling it, poor thing's in a bad way and I feel guilty about abandoning a good friend.

Marcus Dent

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As a fan of British bikes, the Z400 seemed a natural buy. It was one of the few vertical twins of this capacity with the pistons going up and down together. Thus was the even exhaust note very reassuring. Where the Z differed from British bikes was its chain driven balancer, and although those used to Bonnies and the like, will dismiss such affectation as being entirely unnecessary I was mildly impressed with the smooth running, 32000 mile bike.

The fact that it had one elderly owner for the first ten years undoubtedly helped keep the Z400 in nice shape, to the extent that the engine cases were polished to a high sheen and even the chrome front mudguard was free of rust. The 1980 machine was mine for £400. To put that in perspective I almost immediately had to spend £90 on a new set of Roadrunners and a chain and sprocket set for £30. Sprockets are shared, by the way, with the Z440 and Z750 twins, which is useful when shuffling through breakers looking for parts.

After that shock to the wallet, I was even more annoyed to find the front disc pads rattling in the seized up calipers - I'd only ridden in the wet the once! I got away with cleaning up the calipers and putting in a set of EBC pads at £11. They proved a good buy, diminishing wet weather lag and lasting for ages. The chain, though, stretched so fast that I thought the wheels must be out of line, but an afternoon's worth of checking revealed them to be perfectly set-up. I ended up buying a Regina HD O-ring chain which at £50 was initially extortionate but hardly ever needed any adjustment and refused to wear out.

After these hassles it was time to enjoy some serious riding on the Z. Anyone coming from a British twin will appreciate the easy going nature, there's hardly any need to rev beyond 8000rpm, lots of low speed grunt and torque pouring in, making the gearbox almost redundant. I was quite happy to accelerate off with just 25mph on the clock in fifth gear.

Top speed was on a par with a British 500 twin, about 110mph. It was just like a British twin with regards to vibration, a frenzy hitting the pegs and tank, although it was smooth up to 90mph. Where it lost out a little was trying to hold that kind of speed up hills or against headwinds, needing a change down to fourth and some convolutions from my body.....not aided by quite high bars that induced some violent spasms in my shoulders when I held 90mph for half an hour.

I could've fitted flatter bars, but that would have meant rear-sets to match which would have meant making up new gear and brake linkages and probably putting on a seat with a bum-stop - far too much work! It was a lot easier to limit cruising to 80mph, which with a sight crouch was comfortable for an hour or so.

A bike of this age obviously needs more regular attention than a new machine but the Z had electronic ignition fitted and carbs that never needed any work. That just left a tweak of the camchain tensioner and tappets every 3000 miles plus 1500 mile oil changes. The engine was completely oil tight and never used a drop between changes. With consumables that never needed any attention, long tours were in actuality much easier than on some massive four which ruined its tyres, chains and pads in a few thousand miles. Sometimes, more is not necessarily better.

The frame was a strong double cradle tubular affair that had more than adequate support for the steering head and swinging arm bearings (taper rollers and phosphor bronze respectively, according to the past owner), which looked perfect, but only because it had in the past been powder coated. Again, the Z400 sat solidly on the road in the manner of a sixties British twin, although this came not from the original design but a set of Koni rear shocks and front forks that combined a brace with heavy duty springs and thicker oil than stock. The integrity of the fork seals were ensured by gaiters and the only time I looked at the forks there wasn't any sign of pitting.

It didn't take me long to realise that I was the proud owner of a remarkably well sorted motorcycle that had been lavished with an intelligent dose of tender loving care. This was in marked contrast to the second Z400 that I bought which was little more than a field bike but ran and only cost £75. At that price I figured it would be a useful source of spares for the main bike. Its main fault, apart from a wretched appearance, was that the electrics had been completely degutted, the ignition run on total loss principles. This one would run for about 50 miles on a battery charge, which was long enough for me to decide that it wasn't so far gone that it could not be cheaply renovated.

This was aided by a crashed and blown Superdream that was haunting the corner of my garage. After having the alternator rewound I transplanted the whole of the Honda's electrics into the Kawasaki's chassis. There seemed to be a couple of spare wires but I wound them on to some others after consulting the two machine's manuals. Apart from some earthing faults, it all worked well together.

That just left putting a silencer on to the 2-1 (a Superdream silencer was persuaded on) and a few coats of Hammerite's finest. One MOT later I had a second Z400 on the road. It made an interesting contrast with the well cared for Z, giving out a surplus of vibration at all revs and only being good for 45mpg and 90mph. A friend fell in love with this rat and gave me £250, the Z then amazing everyone by lasting for 18000 miles without any attention whatsoever. It finally ground to a halt when the crankshaft went. It's still running but with a GPz305 motor shoehorned in.

Meanwhile, I was riding the good bike every day, proving a wonderfully cheap, cheerful and quick way of beating the commuting hordes. I had to wait for 15000 miles before the engine needed some quite serious attention. The balancer's chain was shot, an amazingly complex job to sort out. Once done, though, the resulting smoothness was remarkable, the bike able to hit the ton without too much vibration.

I celebrated 50,000 miles on the clock with a 5000 mile canter down to France and back again. Brilliant riding with hardly a spot of rain. With the bike doing 60mpg (compared to 50mpg during the commuting chores) and my sleeping in a tent it was dead cheap, too. You can buy a crate of wine in France for the price of a single bottle over here! Apart from two oil changes the sturdy Z400 required no attention and ran relentlessly at 70mph. I kept annoying some guys on FZR1000s, who would speed off at some incredible velocity but have to keep stopping due to chronic discomfort. I once ended up at the same campsite and the poor kids were bent almost double for a good hour as they tried to straighten themselves out.

I could do 400 to 500 miles in a day with only the mildest of twinges in my legs, arms and backside. The only thing that went wrong with the Kawasaki was a silencer bracket fracturing (it wasn't a standard exhaust....) which led to a visit to a French blacksmith's who made up a new bracket whilst I waited. He used to own a sixties Bonnie and regaled me with tales of his youthful exploits, mostly with hand gestures as his English was as dubious as my French. I ended up staying the night in his house, somewhat in awe of his massive family and getting legless on cheap wine. So, the failure of the exhaust was a blessing in disguise.

About a 1000 miles after that trip fuel started dripping out of the back of the petrol tank. No-one was willing to weld it for me and I could not find any in breakers. I drained the tank, took it off and knocked away the rust, which left a two inch diameter hole. I tried GRP but it didn't hold, the debris made an even bigger mess of the tank. Two plates bolted together and bonded with Araldite looked promising until I put some petrol in and it started to leak again.

The breaker let me measure up various tanks and I ended up with an alloy racing job that someone had deemed suitable for a GT250. It was the right length but the fitting at the seat end didn't line up; nothing a couple of bungee cords wrapped around the tank's flange and frame couldn't sort. A month after doing that I picked up a perfect tank for a tenner in an autojumble. Typical.

A mild prang with 57000 miles on the clock made me think it was maybe time to pension off the machine, but it only cost £20 to buy a used wheel which had a disc several mm thicker than the worn original.

Shorty after that the seat fell apart and both mudguards finally rusted through (they were undersealed). The seat was fixed with GRP and the guards replaced with plastic items. The chassis seemed to be wearing out as the front wheel bearings went and the back wheel's spokes started breaking up. Some wiring faults were also blitzing the electrics, with blowing fuses and malfunctioning lights. It became a bit of a pain in the dark as I was never sure that the lights were going to last the distance. Still, I kept going to 65000 miles when I decided it was time to sell the bike before it cost me serious money. The engine was rumbling a little so I was happy enough to take £275 for it.

Eric

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Motorcycles! I hate them as much as I love 'em. Hate them because of what happens when the British weather turns nasty. Love them because even small bikes like the Z400 can give a kick. Hate them because, at least with old bikes, some problem always turns up just as you're desperate to get somewhere. Love them because they can make mincemeat of even the craziest traffic jam. Hate them because if you fall off it hurts like hell. Love them because they're so macho...

Enough! Suffice to say that the 1980 Kawasaki Z400's my sole form of transport, used all year round. I've been riding motorcycles in the same way since the British motorcycle industry ruled the world; in the context of Triumph and BSA twins the Z's pretty damn good! At least I don't leave a trail of chassis parts in my wake.
Kawasaki went to some lengths to quell the major problem with vertical twins, vibration. As is the case with British twins, its pistons move up and down together - yes, just like having two thumpers bolted up together. The old Triumphs seemed less vibratory than the thumpers because the power pulses were smoother, but this was largely illusionary on the larger twins.

The 350 Triumph was almost as mild as the Z, didn't vibrate to a greater extent, yet lacked the chain driven balancer of the Kawasaki. This didn't worry me in the early days, I just enjoyed the easy power, relative civilization and total reliability.

I bought the bike in 1985, after it'd done just 9000 miles, in perfect shape. Both its exhaust note and overall shape was vaguely reminiscent of the sixties Brits; its power delivery was almost identical to a 500 Tiger. Lots of low end grunt with an intensification of power from 6000 revs up. Beyond 8000 revs, just like the Brits, the excess of vibes negated any possible power gain.

80mph cruising wasn't a hassle. 90mph came up with ease, the ton needed a lot of work on the gearbox and throttle. Once, and only once, I saw 110mph on the clock. The vibration and weaves didn't inspire great confidence in either my own or the engine's longevity. I liked the way the engine could be run down to 1500rpm in top and plod along like an old Panther.

You couldn't just whack open the throttle, though. Well, you could but all that happened was the balancer's chain whirred around in a frenzy and the exhaust note turned sulky. No, some effort on the gearchange was needed. A change that had the same kind of action as a Royal Enfield 250; for those who didn't have the dubious pleasure that means you have to feel the lever in, slow and steady. As the tacho needle didn't exactly fly around the dial this wasn't too great a burden, within a few weeks becoming second nature.

Handling was just as easy going. A natural riding position without any hints of pain, a good saddle and a lack of apparent vibration. I say apparent because if I touched the motor with my boot it became clear that the balancer system wasn't entirely effective and, like the old British bikes, Kawasaki had done some fine tuning of the chassis to dampen out the engine's vibration. It always used to be amusing to watch the shaking hands and jumping eyes of riders climbing off Tritons, and the like, where the engines and frames were ill-matched.

There were limits to the handling. The obvious concern was the plastic tyres, original Japanese crap. At first, I thought these weren't half bad, then it rained. Leaning over into the first bend, at low speeds and thus the most moderate of angles, the bike shot away from under me and skidded off down the road. Pedestrians scattered and screamed as the bike zeroed in on them. My Barbour suit took the worst of the slide down the road; I was thankful that I hadn't opted for nylon with its tendency to melt when heated by the friction of a slide!

Neither pedestrians nor myself were injured, the Z suffering wrecked indicators and bent levers. First stop, after fixing those, was a set of Avon Roadrunners. They made the handling even better in the dry and safe in the wet. Ths chassis wasn't that fast turning but it was intrinsically stable, not willing to throw its 400lbs of mass into a feeding frenzy of wobbles.

Most impressive was that when the suspension was worn out, by 20,000 miles, it still didn't let any of the resulting weaves develop into wobbles. With a stiff frame and good geometry you can get away with a hell of a lot (as often practised by the old British factories).

Good old Girling shocks stiffened up the back end, whilst a new set of springs and thicker damping oil sorted out the front. Quite good really, I'd set the bike up to feel exactly like a sixties Triumph. I also replaced the swinging arm bearings with a phosphor-bronze set and knocked taper-rollers into the steering stem. Nice taut feel with bags of feedback from the tarmac - if you're riding in the winter you should settle for no less.

So far so good. My temper was often tried by the single front disc. The same person who specified this must've had a hand in the tyres. Again, quite impressive in the dry but at the first sign of rain they gave up the ghost. I couldn't believe it, pulling the lever back to the bars with nothing happening whatsoever, the junction coming up at an alarming rate. Some wicked gearbox box work and stomping the back brake lever (a reasonable drum) brought us to a halt in time.

I checked the disc to see if the pads were still there! Wet weather lag seemed built into the system, even with EBC or Ferodo pads there was still a need to keep feathering the brake lever in the rain to keep the water off the disc. I don't know how the Japanese got away with such dangerous junk. I tried to fit a Triumph TLS wheel but the spindles didn't match and there wouldn't have been a speedo drive. In the end, I learnt to live with it.

One unexpected cost was the way the various cables wore, often lasting for as little as 5000 miles. This seemed as outrageous as the front brake, until a nylon-lined cable kit was purchased and the cables replaced as they failed. These nylon-lined cables made the controls both smoother and lighter (as well as being cheaper and not yet failing); overall a worthwhile investment.

I never measured consumable wear, like the old Brit's it was never so great as to annoy. The bike's now done 77000 miles - engine parts have consisted of a new balancer chain, camchain, tensioner and set of carbs. The latter became so worn and gummed up with petrol deposits that the running became very erratic, starting almost impossible and fuel went down from 60 to 35mpg! If the bike has a grinding vibration then the balancer's worn out. Maintenance was easy but needed every 1000 miles.

The chassis was surprisingly tough (I'd undercoated the guards and polished the bike every week) with the exception of the exhaust which disintegrated at 24000 miles. A two into one exhaust was a touch loud and brought in a minor flat spot around 5000 revs but was easy enough to adapt my riding style to.

Some electrical problems at 47000 miles convinced me to fit a Superdream rectifier/regulator and do a partial rewire. The battery was always a problem, not lasting for more than two years - I'm not sure if it was the vibes or electrical system. The lights were, at best, adequate. The horn, without doubt, pathetic!

There are always minor complaints about bikes of this era. However, the Z has served me very well indeed over the last decade, although it has not been heavily stressed in the short daily commute to and from work. Compared to running a car, I've saved loads of dosh (on depreciation if not fuel) and still have a bike that I can sell for a reasonable sum. Moreover, every day has had an element of fun that cagers can only dream about. I feel the bike still has a lot of life left in it; at least I hope so, Kawasaki don't make them like this any more.

Terry Perkins

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In work I was complaining of a lack of transport when a colleague admitted that he had a bike for sale. The MOT had just run out and he only wanted £250 for the Kawasaki Z400B2, a twin cylinder four stroke of almost classic lines enhanced by a full Rickman fairing.

The bike passed its MOT first time. The first journey was rather frightening as the bulk of the fairing and the resulting high centre of gravity meant it skipped all over the road. It took some time for me to be convinced that venturing beyond 20mph wasn't going to result in a dose of tarmac rash.

Checking the bike over, I found that apart from rusty silencers it appeared to be in good condition. I was to find out over the next few months that it had been badly neglected and at one point I was convinced that I had made a bad decision because it became increasingly unreliable and soaked up all my spare money.

The last straw came when I went to the local sports centre. The Kawasaki always had to be kickstarted, as the battery could not hold enough charge to work the electric starter. This time it took me absolutely ages to start and then kept stalling when the revs fell below 3000rpm. It was obvious that the battery had finally died - there goes another £20, I thought.

About half a mile from home it died completely. There was a nasty burning smell coming from the coils which had fried themselves. A new battery didn't get it going, so I had to wait three weeks for some very expensive coils to arrive. When fitted, the engine felt much better, the electric start worked and the bike roared into life immediately whatever the weather conditions.

Apart from a niggling front wheel wobble it went well for weeks on end, so good in fact that I paid out for a pair of very expensive Krauser panniers and decided to go touring on the bike.

From Maidenhead to Scotland and back turned out to be a 2000 mile trip done in a mere five days - it looked a lot closer on the map! The bike behaved perfectly and gave not a hint of trouble. I particularly enjoyed rushing to the head of ferry queues in Scotland, although Scottish sheep are suicidal and mad - they wait for the last moment to panic and try to throw themselves under the front wheel. The Z400 coped well with the panic braking and sudden swerves in order to avoid writing off some farmer's romance.

The exhausts had been slowly rotting away, and before the trip had been well bandaged. Despite this, they had been getting more and more noisy, and going along the road at the edge of Loch Lomand at night I could hear the roar reflected off the mountains on the other side of the loch. It was time to buy a new exhaust.

Back in Maidenhead, I bought a two into one system, and found that the old system had been so noisy because the cross pipe had completely fallen off, leaving gaping holes at the ends of the down-pipes. It says something for the toughness of the motor that pistons did not melt nor exhaust valves burn out.

I fitted gaiters to the forks to avoid having the bother of replacing seals at a later date, renewed the swinging arm bearings and bunged on some new shocks - but these didn't help the handling.

At this point I'd spent about £200 in parts, including the panniers. That was two years ago and I have not spent a penny on it since, other than for routine maintenance. The oil is changed every 1000 miles, even then it looks a bit dodgy. Everything else is done when needed - the valve clearances never seem to need adjusting and the camchain (still original) gives plenty of warning when it needs a five minute tweak.

Two secondhand tyres were fitted for its latest MOT, given to me free by the next door neighbour. Lo and behold, the steering wobble vanished. If only I could find such an easy answer to the engine vibes.

Like the Superdreams, the pistons move up and down together, an arrangement that would produce lots of vibration had not Kawasaki, like Honda, bunged in a chain driven balancer. This cancels out vibration at certain points in the crankshaft cycle, but then goes on to produce its own vibes at other points.

The much more sensible route, pioneered by Honda in the sixties and perfected by Suzuki in the seventies, is to have the pistons moving up and down out phase, resulting in perfect primary balance but a torque reaction along the crankshaft (which Suzuki get rid of by using a gear driven balancer).

The only advantage of the Z400's set-up is that it has a nice even exhaust note. The engine vibes are worst at 5000rpm, giving the rider the choice of thumping along happily at moderate speed or screaming the motor at 8500rpm (after which the power dies). Below 5000rpm there is a lack of useful power, it then builds up reasonably to 7000rpm when it comes in properly.

It will run along at 80mph quite happily, but going any faster is decidedly hard work. Handling is far from perfect but generally not dangerous. Weighing around 475lbs with all the equipment fitted, it's not exactly easy to flick about and feels very top heavy at low speeds. Seat height is reassuringly low and ground clearance more than adequate.

The only time I've come off is when trying to overtake a car on the exit of a roundabout. Too much throttle and cornering at the same time meant that both wheels let go at the same moment, the next thing I knew was that the sky was doing circles in front of me. As I slid to a halt, I watched the bike tearing up the tarmac, sending sparks flying.

Apart from the usual broken indicators, the only damage was chamfering the engine cases, fairing and panniers, which is always good for street cred when impressing people with how far you lean the bike over! I picked it up, started it and rode off, only to find the gear lever had been bent inwards and wouldn't change up - a few good kicks soon fixed that.

Since buying it three years ago, I've doubled the mileage to 24000 miles. Long trips have included Wales, Cornwall and Northern France, all without problems, apart from one puncture going over the Severn Bridge. That happened a week after having it serviced by a dealer, who had probably set the tyre pressures too low and had adjusted the chain so tight it had almost ruined the gearbox bearings! Like many other readers, that was the last time a so-called competent mechanic was allowed to get anywhere near the bike.

I generally ride fairly slowly, so brakes and tyres last forever. The front pads were changed when the calipers seized after the bike was left unused for a while, but have done 8000 miles since and the pads have a lot of meat left. Plugs and points are changed at irregular intervals, but usually as a matter of routine rather than necessity.

Will I keep it? Well, after spending all that time getting it to run properly, I think I might as well keep it until the engine or gearbox dies. I think the looks have got better with age and it's now the kind of bike you can just leapt on and ride and ride without worrying about it.

D.Green

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I must be the world's greatest Z400/440 fan. I've owned six of the beasts. Why bother? Well, they were all cheap, had more than enough performance, didn't cost much to run and were kind of fun. The first one I bought was over ten years ago, a bit of a rat in appearance, but the 400cc engine was still punching out the torque.

That's about all it does, power never masses itself into spine challenging proportions. That's okay by me, though, 70 to 80mph cruising is all that I need. 60mpg economy is most welcome, as are long lasting consumables - I've got as much as 20,000 miles out of cheap tyres.

Wear does hit the transmission badly, making it hard if not impossible to ride below 40mph in top gear. There's enough torque to go much slower but transmission slop makes the chain feel like it's trying to leap off the sprockets. The whole gearbox has a somewhat rotten feel to it, whether in a low miler or something that has done over 50,000 miles. A slow, precise and steady foot is needed.

As vertical twins go it's a bit of a mixed bag. A mere two valves per cylinder that are easily adjusted. A reliable camchain tensioner. Twin carbs that need balancing every 500 miles when some wear gets into them (after 15000 miles). As the pistons move up and down together, in the tradition of all those old British twins, the engine needs a hefty balancer system that's chain driven. Wear of the system can cause wild vibration, the major limit on engine life (around 60,000 miles).

Top end hassles have also been known. Usually naff rockers, sometimes camchain bearings or lobes. Piston rings often go around 40,000 miles, needing a rebore if they have the chance to do any damage. All these problems are fairly evident in engine noises, smoke, temperamental starting and poor performance. These days, spares aren't readily available cheaply, but many owners have a spare bike or two to throw in as part of the deal. Pure rats can turn out expensive propositions.

Chassis rot is another perennial problem with these bikes, but not until after 30,000 miles. I think it's our British winters that does for them. I bought two Yank imports that were in immaculate condition despite being over a decade old. You don't see any which are native to this country in such a nice condition. Even after a complete chassis respray, rust still seems to seep out of the metal and the level of white gut-rot on the alloy stymies even bead-blasters! They often end up as gunge bikes with the odd splattering of camouflage paint. I hate those kind of abortions but they do come cheaply.

By now, the best thing to do with the front end is dump it. The single disc brake's nasty in the wet and not that powerful in the dry. The spindly forks were crap from new but adequate for the minimal speeds involved, though on a good day the Z will top out at the ton. The fork's bushes wear out at an alarming rate. My favoured solution is an early seventies Triumph T140 front end with the conical hub, but that means you have to fit the back wheel as well as the speedo's in the latter not the former. Odd designers those Brit's.

Coupled with a nice pair of Girlings, that gives a very taut, precise ride that, not surprisingly, will have British bike devotees all aglow with nostalgia. Especially as the engine sounds and knocks out the power just like an old Triumph T100 Tiger. By the way, the Z400 sounds real meaty on reverse-cone mega's. I've disappointed no end of enthusiasts when they looked up expecting some old relic only to find me on my Jap crap.

Even on stock suspension handling's solid enough, more a case of ignoring minor weaves than worrying about speed wobbles. All of that disappears on a good set of forks and shocks, indicating that steering geometry and weight distribution are pretty near spot on for a mild 400lb motorcycle. Obviously, running on large, thin tyres limits adhesion but it's a slow reacting bike and wholly lacks the sudden naughtiness of modern machines with sixteen or seventeen inch wheels.

Comfort is down to how much effort the rider puts in. Eh? On a bike of this age you can't expect the seat to be in good fettle or the bars to even be stock. It's easy enough to fit a decent seat and slightly raised bars (to match the forward mounted pegs), which results in reasonable comfort up to 70mph.

On one of my bikes I had flat bars and rear-sets, could cruise along at 80mph, though it was a bit pointless as above 75mph the whole machine started to thrum away as the primary vibration got the better of the balancer system. On another bike I had stock pegs and ape-hangers, which made it well laid back for my daily commute through London but made A-roads a pain any time I went above 60mph. With its classical styling I could never bring myself to fit a fairing.

Looking back at over 150,000 miles on the beasts, one surprising, even shocking, realisation emerges - I've never had an accident or fallen off. Part of that because I'm a boring old fart (but I'm still here, so there!), the rest down to the steady way the Z reacts and the instinctive way I ride the thing without any thought. I know their limitations and what to expect, so there are no nasty surprises.

The latest one is a 6000 miler from the States, all nicely shining and running really beautifully. It's hard to understand why the Yanks don't ride higher mileages but it's very nice of them to keep the bikes in such great shape. I paid £1200 for this one, which is a lot more than I would normally spend on a UK sample. The cheapest being the first rat at £150, which was a real bargain as I cleaned it up and fitted better suspension, ended up with a very useful little bike. Expect to find something with some life left for around £500 and go up to a grand on the private market for the really nice ones. Yank imports go for £1000 to £1500 - if you hunt around you can find some really good deals, though I have seen a few that have been cleaned up and clocked!

If you speed, look elsewhere. If you want the kind of British twin that Triumph or BSA made in the sixties, with the sophistication of Japanese engineering, then the Z400's well worth a look.

Rick Wellington