Kawasaki GT550

A disgruntled DR sold me his well worn '85 GT550 just as my own GT was due for the great scrap yard in the sky. My own bike had done a credible, maybe even incredible, 234,500 miles! The replacement a mere 84000. GT's are usually good for 100,000 miles before the motor needs a complete rebuild. Judging by the consistency of the oil in this one, expecting another 16000 miles was perhaps pushing my luck, but in the world of hard ridden despatch cycles stranger things have happened.

The GT sported several mods. A front end off a GPz1100, not because the GT550's forks were particularly nasty, just that they'd been bent beyond redemption, courtesy of a big red bus. The rear shocks were off something else as well, only reacted to the most vicious of pot-holes. Despite these mods directional stability was of a variable nature, the front end tracking as true as a supermarket trolley with one wheel locked up! A dramatic improvement resulted when I backed off on the steering head stem, which had been tightened down with gorilla force. It was just possible that the previous owner had done this as a joke; he was renown for putting spuds down the ends of fellow DR's exhausts. We wished him well in his new profession of collecting garbage.

Performance was what I'd expect from a well worn GT550 engine. Good for the ton, with sufficient city acceleration to see off most hot hatches. The motor was a bit wide to sneak through the narrower gaps but a blast on the air-horns usually sufficed. GT's are not light, weighing in at 450lbs, which together with conservative steering geometry make them a bit on the tiring side for extended despatching, but it's something I learnt to live with.

The electrics on old Kawasakis are another matter. Rotting wiring combines with excessive vibration to cause sudden failure of the ignition module, which needs more rubber mounting than stock. Replacements are rare in breakers, so the problem is potentially very expensive. Batteries that boil over and leads that short out due to the insulation falling off can also be expected. Lights are adequate for mild out of town excursions but a set of spare bulbs are essential extras.

My GT had a reluctant starter, so I usually left it running - it was so nasty looking that no self-respecting thief would bother stealing it. On one occasion I came back to find some urchin playing with the throttle, trying to see if 10,000 revs would break the engine. I broke his head with my fist before he had a chance to find out. I doubt if he pissed about with anyone else's bike after that.

The GT's a sensible motorcycle, the most obvious feature, save for the bland styling, being the shaft drive. This works so well, fades so completely into the background during town work that a lot of people completely forget its existence. In fact, it needs its oil changed once a year if you don't want to become an expert at replacing universal joints. I'd put some new oil in when I'd changed the engine oil.....only a thimbleful of murky white stuff came out of the drain plug. It wasn't that much of a surprise, then, that the shaft lurched, chattered and whined away.

It didn't help with the power delivery. The stock exhaust had long been replaced with a four into one of obscure origin, which blighted the engine with several flat spots. Along with the ambiguous shaft, there was quite a lot of delay between opening the throttle and the power arriving at the back wheel. This is not unusual on GT550s, so I was pretty used to having to carefully orchestrate my overtaking plays in traffic but would sometimes be caught out by the lack of instant acceleration.

One time, I was pushing the bike hard through a gap in braking cars to roar across a junction before the lights turned red. The bike stuttered rather than accelerated, then shot forward just as eager cars were hustling at right-angles across my path. The barrage of horns had the noise of dying metal added to them when some observant lout whacked the GT. The wobble was spine rattling, but the Kawasaki twitched forwards rather than spinning off the road. As someone had back-ended the cager who'd whacked me I didn't stay around to argue the semantics of light hopping. My hands shook for the rest of the day, which was penance enough!

The worst thing you can do when despatching on a bike like the GT is to skimp on tyres. Greasy London roads will soon have you off; even if your speedway techniques avoid that nasty end, eagle eyed Mr Plod will be only too happy to ruin your day. The eagerness with which they book motorcyclists makes me think they are on commission. I favour Metz's which have superb grip whilst lasting for more than 8000 miles. Cheaper tyres last better but you end up paying more for broken bits than what's initially saved!

GT frames are pretty tough, an accident will have to be so serious to bend them that the rest of the bike will be written off. The most serious cycle part debility concerns the petrol tank - after 75000 miles rust eats into it, causing it to go wafer thin. I've suddenly found myself with a lap full of petrol on more than one occasion. Poor engine running may well be down to a blocked filter. Finish on my bike was pretty appalling, with wheels and engine vying for the thickest layer of white crud and great scabs of rust on the frame and swinging arm.

The only reason the front twin discs worked was that they were off something else and had, anyway, been rebuilt several times. Stock GT discs get a dose of premature seizure every month in the winter, every other month in sunny weather, although they are reasonable for the first 15 to 20,000 miles. I reckon one breaker runs his Porsche on the profit he makes out of selling GT calipers!

The one thing that makes these bikes so popular with despatchers is the relentless way the engine keeps running without needing any regular maintenance, although the more conscientious owner changes the oil every 2000 miles. Carbs and valves rarely need much attention. Its only substandard component is the hyvoid primary drive chain which starts to wear out come 75000 miles, though some last for more than 100,000 miles. Camchains and tensioners often need replacing at 50,000 miles, though there are some that have gone around the clock on the originals!

Eventual engine demise is down to the crankshaft bearings, an expensive proposition to repair. Depending on the regularity of oil changes, camshafts can wear rapidly or outlive the engine. Surprisingly, the bores and pistons keep going for well over 100,000 miles. There's a lot of potential in these motors for extremely high mileages.

Not, alas, in my example. After a couple of months, with slightly less than 90,000 miles done, great clouds of oil were burnt off through the exhaust. After a couple of days of swathing London traffic in a great cloud of pollutants, I gave the weekend over to taking the motor down. Taking out the engine is really a two man job but I managed it, with an excess of curses, all on my own.

The motors are notorious for stripping the head studs, so I was doing well to only have two go by the time I'd prised the cylinder off. Turned out two of the small-ends had worn, causing the pistons to flop about, destroying piston rings, which sends lots of steel around the engine. It wasn't worth the effort to try to repair the motor.

One of the really neat things about GT550s is that they are still made. A bit of phoning located a crashed 9000 mile motor which went straight in. The carbs would not fit until some creative bodging was applied, which meant dumping the air filter. As this was full to bursting point with a decade's worth of crud it was no great loss. After a few incantations the new motor growled into life and I was back in business.

The acceleration was transformed and top speed was a somewhat startling 120mph. Fuel stayed the same at 45 to 50mpg. Vibration was only apparent above 6500 revs, unlike the old engine which in its final days felt like it wanted to leap out of the frame even at tickover. The shaft drive had started to make a terminal knocking noise that discouraged me from exploiting the new found turn of speed. When someone offered me a decent wedge I gave in to temptation..... apart from anything else it was November and I felt like spending the winter in Africa. I sold off all the accumulated stock of wrecked GT motorcycles as well.

Despatchers love GT550s, and to a lesser extent the 750 version, because they are so dependable, even at mileages that would have most other motorcycles falling apart under them. Throw in loads of cheap bits and even whole engines from breakers and there are few other machines that can match their usefulness.

I’d prefer something lighter, faster turning and more economical. Arguably, a bike like the old Honda RS250 was much better suited to London traffic, but engines that wore out in less than 20,000 miles didn't make too many friends for this otherwise excellent little thumper. Kawasaki's GPz305 was another tempting alternative, but proved even more unreliable than the RS.

By the time you read this I will be in Africa, when I have to come back to the UK to turn a wedge, I will probably start despatching again. I may well go the GT550 route again, about the only sensible alternative I can think of is the Suzuki GS450E, another reliable motor that's been around for ages.

Martin Granger

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Most tales of the GT550/750 involve massive abuse, despatch riding and total neglect. It says a lot for these bikes that even when so subjected they keep going against almost impossible odds. My five year old GT550 has never been despatched, rarely has it been thrashed into the red and it's given a cursory service every 2500 miles. The result of such a relatively civilised life is 110,000 miles on the clock.

I actually bought a stolen-recovered GT550 when mine had done 75000 miles because it had begun to run roughly but this didn't become any worse so I kept the old motor in there, intrigued to see how much longer it'd keep going. I bought the bike with all of 1500 miles on the clock, the engine so silky that I felt sure that the running in had been performed properly.

The only initial problem I encountered was changing down through the gearbox. Changing up was as smooth and slick as I could imagine, with no intrusions from the shaft drive - it made BMW boxers look like the old relics they really were. But going down through the box was vile, it was as cantankerous as the twenty year old MZ 250 I had in the garage (waiting for it to become a classic). It became better by the time 3000 miles were on the clock, but went off again after 45000 miles. It was most interesting in the wet, when a little inattention would produce a madly hopping back wheel.

That showed up the Japanese rubber as a pile of junk. Various brands have been tried over the years, Roadrunners having the best combination of grip and wear, although they were slightly thinner than stock and not recommended for the GT. I could get at least 15000 miles out of them, ride with them down to 1mm without any large wobbles and the slides, due to the back wheel locking up or diesel on the road, were always controllable, thanks to the big wheels.

That large wheel, I felt, always aided stability. I had expected it to be a bit of a handful in town, with its 450lbs of mass and conservative steering geometry, but it was dead easy to throw around, somehow encouraging me to ride it like it was a frenzied stroker rather than a middleweight tourer. The bars were only moderately wide and the engine width, even with mandatory engine bars, was not too excessive. Few were the gaps that I did not thrust through.

The horn was a pathetic squeak, my cat made a more piercing noise when I accidentally sat on him. Car drivers completely ignored me, probably figuring it was some infant on a bicycle. A set of air-horns soon solved that one, had great fun knocking out a dirge like a ship lost in fog. Unfortunately, the bracket to which they were fixed fractured, sending them tumbling down the road to be flattened by a following police car. They booked me for not having a horn, but the paperwork never caught up with me!

That was at 19000 miles, with nothing more than servicing and consumables necessary. To compensate for the poor note of the refitted horn, the silencers had rusted out their baffles, allowing rather more noise into the atmosphere than the manufacturer had intended. I loved the whine of that engine, but by 22000 miles the silencers were threatening to fall off. Motad time. I had great fun knocking the old silencers off with a hefty hammer but the downpipe's nuts preferred to snap off rather than come undone.

It took a whole weekend to put on the Motad 4-1. There didn't seem to be any extra horses, stock gives 56hp at 9000 revs, but there was a bit of a glitch between 5000 and 6000rpm. This was no great loss as the footrests had always been attacked by vibes at this particular rev range. The aircooled, DOHC four lacked any form of engine balancers, but the secondary vibes were only really noticeable at that rev range and when thrashed into the red. The bucket and shim valves, all eight of them, needed shimming about four times, something I left to the dealer as it's a very tedious business.

The carbs I could balance myself, about every 5000 miles, which just left the oil every 2500 miles and the filter at 5000 miles. The camchain tensioner was never touched and the original camchain is still there - can this be a record? The only sign of age the engine exhibits is a lack of willingness to rev beyond 9000rpm and a disinclination to put more than the ton on the speedo (it's gone through about ten cables).

That doesn't bother me as I quite often cruise along at no more than 65mph, these days, only very rarely doing more than 85mph, although that is a speed the GT can quite happily hold until the tank runs dry. Fuel hovers around 45mpg but used to do 55mpg in its prime. The worst I ever got was 36mpg, a near 100mph thrash along a German autobahn. With more than four gallons in the tank, the range matches the comfort afforded by the sensible riding position and well shaped seat (I'm on my third, they eventually soak up water through tiny cracks).

The most I ever did in a day was about 750 miles, which produced some slight cramps but I was ready for the road again after a good night's sleep. The GT had then done 45000 miles, purred at tickover after the hard day's riding like it had come straight from the crate.

Not long after that thrashing some oil started leaking from the cylinder head gasket, ruining an otherwise still shiny motor. The black engine finish had not flaked off to any discernible extent. Tightening down the cylinder head studs stopped the flow; something I had to do every 15000 miles or so thereafter.

Other oil leaks came from a wrecked gearchange shaft seal and from a blown engine sidecase gasket. The latter showed up the old bogey of stripping screw threads (at 61000 miles) but a combination of a helicoil kit and Araldite was sufficient to get the threads back into shape. Any internal engine job threatened to turn nasty because of the poor quality of the alloy, although everything that was stress bearing was well built.

The only serious engine failure was a slipping clutch at 79000 miles. It had started to drag at junctions well before that, causing me to abuse it relentlessly which, no doubt, didn't help its longevity. The drum looked oval so a mildly used unit from a breaker was put in, which is still functioning. I almost ruined the engine when the oil cooler hose fell off. It happened in town and some helpful pedestrian started shrieking abuse at me as it was spraying off the bike on to what looked like her best summer dress. I wedged it back on and rode off before she turned vindictive. It was just as well that I caught it then because the hose looked very threadbare and due for replacement.

The air assisted shocks were dead meat after a mere 20,000 miles, Koni replacements go for about three times that but didn't seem much better than stock (when they hadn’t lost all their damping). Kawasaki put gaiters on both the shocks and the forks! The latter are still original but I refurbished them at around 60,000 miles, when they became very loose. Normally, I couldn't complain as they were a nice compromise between absorbing large bumps and keeping the front wheel where I wanted it......readers will have realised by now that I am not a hard rider, but then the GT is not a racer, so we are as well matched as the suspension.

The sensible design of the GT550 extends to a neat drum rear brake. Fine until 70,000 miles when using the brake made the back end feel like it was falling apart. This proved to be no illusion as there were hairline cracks in the cast wheel. Maybe due to the time I had to ride up a pavement (I'd saved the front wheel by doing a minor wheelie, not easy on the GT) or maybe down to old age. Replacing this also revealed that the splines in the shaft drive housing were totally without grease and well worn, so those bits were replaced with newer items from the ever grinning breaker. Apparently, every time the back wheel is pulled out you're suppose to put some grease in, but no-one told me so I never did it. The new bits made absolutely no difference to the clanking, malicious gearchange! By then neutral was absolutely impossible to find, even when new it had been awkward to locate at a standstill, involving much pushing and shoving, not to mention swearing.

The front brakes - powerful discs - would throw me over the bars given half a chance. The only things to upset them was winter salt (when the calipers would corrode) and ageing brake hose (when they went so spongy that the lever would come back to the bars). I went through six sets of calipers, two sets of discs and eventually fitted Goodridge hose. Pad life was in excess of 12000 miles.

The rest of the chassis is still in reasonable shape, just a bit of touching up of the paint necessary, although the Motad is about due for replacement (I have to wear ear-plugs). It's really a rock solid kind of bike that grows on you with every passing mile. Its sedate lines have worn well, giving a classic appearance that is all the more pertinent with the rise of the retro. I’d buy another one without hesitation but I don't have to as I have a spare engine ready and waiting.

M.R.

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A 1987 despatch hack, gone around the clock at least once, but a worthwhile project at £275. The first thing to do was buy used but not too worn consumables. The second thing was the MOT, at a friendly back street mechanic's. The third was a bit of a test run, a taste of black neglect and rotten old age. The engine made noises like it was going to explode but put the ton on the clock. The air-adjustable front forks were leaking, inducing a yawing motion above 60mph.

The brakes, twin discs and a rear drum, were mightily powerful; the wheels and brakes had recently been replaced with newish stuff. A necessary safety measure on any bike that has done over 100,000 miles, as there's always the chance they may crack up. Finish on aged Kawasaki wheels is appalling, so it was a bit odd to have a rat bike with a pair of beautiful wheels.

After asking around I found out that the motors do rattle a lot after the first 40,000 miles, that it doesn't necessarily mean it's about to die. The weakest element's the camchain, which may need replacing after as little as 30,000 miles. They are otherwise quite capable of doing over 100,000 miles - some have done over 150,000; one tough cookie.

After a month I was sufficiently impressed to do the cycle parts. I replaced the petrol tank with a newish one before the rusted out sides caved in. Having experienced one bike that caught alight whilst I was riding along, I didn't want to encounter another. The panels and guards were sprayed with an aerosol can I just happened to have handy. A new seat was acquired from a dodgy character who made Arthur Daley look like a born-again Christian. The exhaust system was bodged with universal silencers on the end of the stock 4-2 headers. The wiring was tidied and a new (cheap via mail order) battery installed. Old inner-tube cushioned the black boxes, battery, seat and petrol tank as quite a lot of vibes came through above 7000rpm.

The engine was curious in a machine with such a staid, functional appearance. 56 horse were claimed at 9000rpm, but internal wear and the twists and turns of the shaft drive had reduced that to 35-40hp at the back wheel. Most of the power was made above 7000rpm. Between 5000 and 7000 revs there was a lot of surging and gurgling, a reflection of either wear in the carbs or bad design. Between 3000 and 5000rpm the bike burbled along happily enough but without much by way of power. Below 3000 revs the transmission made a hell of a racket, as if there was a chain trying to leap off the sprockets rather than a shaft drive.

Before all the devoted GT riders write in to complain bitterly about this slagging off, all of this is in the context of an old rat. It wasn't so much surprising that the gearbox was something out of a BMW owner's worst nightmares but that the engine still ran at all. Most of the hassles I could ride around, used as I was to nasty old Jap twins. In that context, the GT was fast, comfortable and well appointed.

It took me a while to get around to the front forks, as a lot of my riding was through London where I didn't do more than 50mph and the GT handled perfectly adequately. When I pulled the gaiters up I was met with a veritable forest of rust! No wonder the seals were blown and I had to pump air in every day. The sliders were beyond reclamation. Breakers were visited, brutally twisted forks rejected until a really nice pair were found for £50.

The GT550 weighs 450lbs and has very conservative steering geometry to keep the ruminations of the shaft drive in check. Handling's safe rather than inspiring but the engine wasn't churning out enough power to give me any wild moments. All kind of movements can be conjured if it's abused on minor roads.

With all the recent bits fitted the old girl was looking rather good. I added to this by whipping the engine covers off, having them bead-blasted and polished. The rest of the engine was black, which was easy to patch up. The bike looked a lot newer than it really was, an illusion shattered every time the engine was started up. Total cost at this point was around £400, including the initial £275 purchase price. It was worth £600 to £700 on the used market.

I tried thicker oil in the engine. This can be dangerous as the oil--ways are narrow to start with and time tends to clog them up a little, but the DR had fervently insisted that he'd done the oil every 1000 miles (as did I). I gave the engine the benefit of the doubt and it sounded better, the gearbox was slicker and there was less churning at low revs. Smoothness was further improved by finding a mechanic who could actually balance the carbs. Normally, simple enough but they were so worn that it took a lot of minor adjustments to balance them.

I had some problems with fuel gushing out of the bowls. The float heights varied on a whim of their own. When this happened to the carbs on the inner cylinders it was a major hassle that involved lots of swearing and tearing bits off the bike. The stock airfilter box was soon dumped to facilitate quick strip downs. Much to my surprise, the engine ran harder, the power delivery was smoother and it was a touch faster. Don't try this on a stock bike - it doesn't work - so I can only guess that one time in the bike's venerable life it had run a 4-1 with altered jetting that hadn't been changed.

At one point I took the carbs off, stripped them down, soaked in paraffin and then blew high pressure air through them. This worked, no more fuel lost. The peds in London must've been very thankful - one less crazed biker tearing into Jap iron in the gutter.

Another area of fear and suspicion was the ignition circuit. HT leads breaking down in the wet's common - something you don't want to combine with a leaking petrol tank! The electrics on my bike weren't that old and only gave the odd misfire in the really heavy storms (though they were all too frequent). Mind you, I had a bit of a shock one dark, wet night when I looked down to see an excess of sparks off the HT leads. One of the connections between lead and plug cap was leaking; easily sealed. Some old GT550's are dire in the wet, so check carefully if you're in the market for one.

The GT was running some cheap Avon tyres which were fine in the dry but somewhat precarious on wet, greasy roads. Metzelers are much more secure but are expensive and last for only 6000 miles against more than twice that for the British rubber. I almost fell off a couple of times in Central London...a hurried (motocross boot shod) foot down threw the GT into an alarming lurch but stopped me from getting seriously hurt. DR's hustle around on them all day long without serious incident, so they must be okay.

One worrying moment came when all the electrics went dead but the motor kept on running. I juggled the ignition key and all was well. The same thing happened several times before juggling the key had no effect. The ignition lock was worn out. No problem, just find another in the breakers...shit, all the wiring had changed and I spent a whole weekend trying to match the wires up and make all the electrics function.

The front light seemed to be made for a 125. This was because it probably was. It certainly wasn't stock. I fitted a stock light and then found out why it'd been replaced. The battery kept going flat. I didn't want to delve into the electrical system - God knows what I'd fine - so put the old light back on and suffered eye strain and close shaves at night.

All in all, I got nearly 20,000 miles out of the GT at a total cost of £500 (plus petrol at 50mpg). The engine was really impressive in how it just kept going and going; the rest of chassis wasn't so tough but cheaply replaced with nearly new parts from breakers. When sold, the bike polished up nicely and went for £750, which meant I'd had my biking for free for two years!

Of course, after that experience I went out and bought a one year old GT550 for £2250. Only 4000 miles, absolutely immaculate. The engine was so quiet and smooth it was like I was on a different model. Later bikes share the Zephyr engine - no faster but a stronger midrange and much smoother delivery of power. The handling was almost sporty on the new suspension. It's one Japanese model that's definitely evolved into an improved machine. I'd recommend them to anyone who wants serious motorcycling.

J.T.