Sunday, 4 March 2018

Kawasaki GPz1100


After much searching I found a 1983 Kawasaki GPz1100, the Unitrak model with digital fuel injection, dozens of sensors, black boxes, etc. The owner had it for six years but had apparently crashed it three years previously and kept it in the shed ever since. The frame had been sprayed silver and the 20000 mile engine stripped and rebuilt with a new camchain six months previously, at which point the owner had gone to work in Saudi. Apart from the bodywork it was all in one piece. The wiring was all in place, thank god. The owner had previously spent a lot of time and money - new parts included fork seals, taper bearings, Raask rearsets and matching pillion rests, Telefix adjustable bars, Goodridge hoses and a Micron exhaust.

The seat had been professionally restyled and recovered. The tank featured an aircraft type filler with no room for the normal tank mounted LCD display. No fairing, headlight, clocks, chain or battery, and bodywork bits in different colours were the minus points. My main worries were the engine and fuel injection. Sense told me to leave it alone, and the £1000 asking price was too high. I offered £850 and left the owner’s brother to consult the owner’s wife. They rang back and said OK. Oh shit, I thought, having convinced myself it would be too much work and risk.

A week later the GPz was installed in the garden. The wife looked dubious and the dog disinterested. I decided to spend absolutely the bare minimum necessary until I had got it running and was sure the engine and DFI were OK. Fitting the throttle cable took me an hour and much cursing and lost knuckle skin thanks to the connector placement between two of the injectors and attendant plumbing - not a roadside job! The timing was one tooth out on both cams, but all else was well under the cam covers.

The big day dawned. After tracing a few loose connections the electrics came up OK, fuel pump whirring merrily. Choke on, press the starter button and... 20 seconds later no life. Check for sparks, plenty of petrol reaching the cylinders... tried a few more times, fingered a large hammer and it suddenly whirred into life. The sun came out, the missus smiled, even the dog looked up from chewing its bone. Considering most of the valve clearances were out, the engine was very quiet.

I decided to go the whole hog and spend a few hundred notes putting it back on the road properly. Twin headlamp fairing, set of used clocks, a host of miscellaneous parts and a cheap respray that didn't look very good... the list went on and on, and the budget right out of the window. Just buying a couple of new brackets from Kawasaki got rid of nearly £50. Suddenly, it was all together and ready to try.

My initial impression of the GPz, wheeling it around to the front of the house, was of the weight of it. At 530lbs fuelled up it is at least 50lbs heavier than any of the current generation of sports bikes and the extra weight really is noticeable. The cut-down seat made me feel like I was really sitting deep in the machine, the clip-ons were a long stretch and the rear-sets were too close to the seat.

The urge to take a long route into town via the dual carriageway and give the throttle cable a good stretch was resisted. I decided to give the GPz a gentle shakedown run to make sure nothing had been missed or left loose or badly adjusted. And, so, it came to pass that l was sitting outside the local bike shop with a new MOT and a freshly set up engine. So what’s it like to ride?


Once on the move it feels very light and is quite manageable in heavy traffic. It's very easy to trickle along at walking pace with no need to waggle the bars for balance. The steering felt very stiff at first, almost as if the head bearings were too tight but really caused by the lack of leverage from the clip-ons, the eighteen inch front wheel and the long, lazy chassis geometry. The cure was to adopt a new cornering style, hang out the inside knee and give a firm nudge to the tank with the opposite knee. This is one beast that responds to a knee in the ribs rather than a yank on the horns.

Tight twisty bits aren't the GPz’s strong point, and the rider is quickly reminded about just how much it weighs. Corners need to be well planned and the line well thought out. Once a little, or sometimes a lot, of body language is used, the GPz can be hustled along country lanes at a fair clip and what seems like a daunting bend can be resolved with the application of some muscle.

It has to be remembered that the GPz does have limits and no doubt has a vicious bite if provoked. A roads are where the GPz is most fun, attacking long sweeping bends in well planned assaults and then using the engine's monster power to crinkle the tarmac on the straight sections. Brill.

The suspension does an admirable job of controlling the bike’s excess mass. I run the suspension settings on about 75% of their maximum air pressure (14psi front, 48psi rear) which gives a firm ride when solo on fast A roads. At slow speeds in town this is a bit harsh but I'm too lazy to mess around with it. The anti-dive works well, the stiffening of the suspension gives a lot more feel from the front tyre when you really need it.

The brakes aren’t quite the ferocious things that the road tests talk of. The front lever uses about a third of its travel before anything happens although after that there is plenty of feel, and plentiful if not excessive power. We bled the system again and again, although there are no less than eight bleed nipples on the front system so maybe l haven’t got the hang of it yet. The rear disc brake was totally useless until it seized on; after freeing it off there was a very marked improvement. Pads are OE items that probably haven't benefitted from spending three years in a shed. Also, the GPz is deceptively fast and I tend to approach corners a lot faster than on any previous bike. Bearing in mind this and the mass, the brakes cope well.

The engine is the heart and character of any bike and is certainly the most dominating factor in the GPz, whether you are riding it or just looking at it. The engine is physically huge and the alternator and timing gubbins hanging off each side make it very wide. Also very, expensive if the plot slides up the road on its side. A used set of engine bars were quickly acquired, the additional width more than compensated for by the extra peace of mind.

I had found the engine felt very flat and rather vibratory at low revs. After 3500 revs the engine reveals its schizoid nature and 100 or so horsepower stampede out. Not in a stroker kind of fashion but most unlike the sort of power curve you would expect from a big four stroke. This sudden power kick can catch pillions unawares and one poor friend spent most of his trip with his feet sailing up and down past my ears. Making quick progress in the wet is a dodgy business.

The vibration is most intrusive around 3500rpm and can be quite painful on the hands which take most of the body weight. The engine becomes vibration free at 4000rpm. At 5000 revs a mere twitch of the throttle releases a hell of a lot of power, and in top gear equates to 90mph. The vibration isn't really a problem as I spent most of my time sweeping up and down the rev range enjoying the arm stretching acceleration. Grin factor - 10! Fuel consumption? Don't know; stop asking me silly questions and go buy an MZ.

The exhaust is rather loud and I’m honestly amazed that it carries a BS stamp. If it wasn’t for the huge expense of replacing it, I would. Honest. Otherwise, I’m quite impressed with it after the initial hassle the finish is good, it tucks in very close to the bike yet still allows access to the oil filter and retention of the main stand.

The pattern fairing does such a good job at keeping the windblast off that 90mph seems like 50mph. The pillion passenger, perched up high, does catch lots of turbulence. Otherwise, the pillion is free of vibes and quite comfortable. The fairing mounted mirrors are totally useless unless you’ve got perspex elbows; life expectancy of my licence is not good.

The switches and clocks are very good. The LCD panel, relocated in the fairing, is basically useless. The fuel gauge is inaccurate, causing the warning lights to flash annoyingly long before reserve is required. Unless the battery is kept topped up to the brim, the warning light also flashes under hard acceleration. Hands up all those GPz riders who have looked down, when the LCDs were mounted on the tank, and then ridden into the car in front which has just braked. The previous owner of my bike did!

Problems? Yes, a few. The bodged on fuel cap leaked so a large bolt-on one replaced it at a very cheap £16 from Harris. Vibration caused the rear mudguard to fall off, fortunately at walking speed; if I had been going faster it could have locked up the back wheel and been very nasty. A few other bolts vibrate loose, so a regular checkover is needed.

So, what have I got for the £1800 the bike has cost me in total? Well, for a start, I have a bike that is definitely not just another GPz. It never fails to turn heads, even parked amongst the race replicas. lt has a real character and personality, and for me there is great satisfaction in having built the machine up, knowing every nut and bolt. Am I pleased with it? Does a shark shit in the sea?

Would I buy another? Well, actually, no! Much like a CBX1000 or Z1300 it’s a bit difficult to think of a reason to buy one. There are plenty of other bikes that will run rings around the GPz which are also cheaper. But, then, love and logic never were good bedfellows.

Andrew Wood

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