As you all doubtless know, the GPz was introduced in 1981. Kawasaki, with their reputation for bullet-proof motors had, in many ways, redesigned their Z1000. As well as a restyle they claimed a mighty 108hp at 8500rpm, nearly 140mph and standing quarters of just over eleven seconds. The GPz had enlarged bore, larger valves, wilder cams, high dome pistons, lightened crank, oil cooler, a partridge in a pear tree and various odds and ends. Back then, it was the business.
Coming home from work one wet night to find the phone ringing, some chap with a GPz for sale, £1200. Three sleepless nights later the weekend arrived and I went to see the bike. On inspection, the GPz was immaculate despite being almost six years old. It had a Lawson seat and endurance four into one - it sounded as good as it looked; I was hooked. Perhaps, if I could have foreseen the future trials of ownership my enthusiasm might not have been so great.
First impressions were its mass (650Ibs), smooth drive train, spongy, soggy brakes, low speed heaviness and vibration through the bars. As we were in the middle of a housing estate, I couldn't really goose it, but all seemed fine on the test ride. I returned and paid the man his money (he wouldn't haggle).
The 40 mile ride home was quite interesting. Out onto the main road, not much traffic (amazing), see what it can do. Up to five grand, this is no highly tuned monster growling for revs. The fuel injection and electronic ignition make it perfectly civilized - tractable even docile, However, as you wind it on, the power floods in, the surge can only be described as hyper space rapid but not violent; in a word, controllable.
Top gear roll-ons from as little as 25mph are no problem, just open the throttle and go, with instant take up from all throttle openings. The bike ran up to an indicated... cough, cough, morning officer... until I thought better of it (yes, that is a good way to say that I bottled out, better get used to it first, I figured).
Handling was a very serious brown trouser affair, thanks to the strange combination of tyre sizes and makes (3.25x19 Continental front, 4.25x18 Goodyear rear). The handling suddenly became very nasty, like riding over a bag of eels. Careful examination revealed a puncture. Not a good start. Pumped it up at the next station and continued home, only to take a bend on the wrong line trying to avoid a pyramid worth of horsey Richards The Thirds. Inspired by a rapidly approaching large stone wall with spikes, I soon found out that it could be well leaned over and was quite manoeuvrable for such a large piece of iron.
Back home the bike was given the once over, new pads fitted, oil changed and the puncture repaired. The exhaust system meant the centre stand had been thrown away, so I bought a paddock stand - ever tried putting 550lbs onto one of these on your own? You have to pull on the grabrail while kicking the stand into position. Great fun. General servicing is straightforward, as per most big Kawasakis.
Things to watch for are weak caliper bolts, rusting around the tank badges, electrics and bearings in the swinging arm and steering head (mine were good, needle and taper rollers, respectively). Front fork seals go at an alarming rate. The bike was treated to new tyres, I should have preferred Metzelers but couldn't afford them, so Dunlops were shoved on. They were quite good and lasted for 6000 miles.
With decent tyres, handling was OK in most conditions. The GPz was used for commuting to work and general pleasure trips. With winter coming up, I figured things could turn interesting. The large tank held 4.7 gallons and the bike did 36mpg hard ridden and went up to the mid forties under normal usage.
The fuel gauge was useless, registering full until it suddenly dived to empty. Both oil and filter were changed every 1500 miles. I still wasn’t happy with the brakes, so new master cylinder piston and seals were fitted and the fluid bled. The bike already had stainless steel hoses so it was the only thing I could try. It worked, firm brakes at last, almost made the four hours in a freezing garage on a November night worthwhile.
Up to 80mph the riding position was comfortable, beyond that the wind blast became very disconcerting. Also, at such speeds, the vibes through the bars were bad enough to make my throttle hand numb after 30 miles. The bike was used a lot two-up, my fiancee finding it very comfortable, thanks to the seat and the effectiveness of the Koni rear shocks. Once under power, handling was no real problem and it felt quite safe in the wet.
As a workhorse, the bike was treated to cans of WD40 and Duckoil every third day around the engine and electrics - with winter approaching I didn't want it rotting away too quickly.
The box of tricks (computer) is hidden away in the tail unit. Replacing the rubbers that fix it to the bike is quite important as they tend to wear away, allowing the vibes to attack the computer. Am I the only owner paranoid over computer failure? Lifting off the seat reveals an Aladdin's cave of nightmares.The air flow meter is a heavy thing with a large multi pin plug under the seat, the air filter fixed on its back, the whole assembly pushed into the surge tank housing. A smear of Vaseline or grease should be applied to the male end of the meter for an air tight fit. Under this lives the usual 12V 16AH battery.
The next point of interest, children, is the throttle valve switch on the left hand injector. It has two lights, a green one comes on when the tickover mixture is correct, then goes off when the throttle is opened and a red light then comes on if everything's working properly. Although the engine looks very neat, hidden away there are any number of frighteningly complex parts needed to keep it running.
After several months a slight misfire occurred. The bike started as usual, but as soon as the throttle was opened it would stutter, fluff, bang and stop. The maddening thing about it was that one day it'd be fine, the next it'd stop every 100 yards. Going to the work in the winter, frosty, pouring with rain and stop-start, stop-start, was doing my temper no good at all.
I tried to check it over but there were, according to the manual, so many things that could go wrong fuel pressure, computer failure, throttle valves, air flow meter, wonky ignition - the list would fill two toilet rolls and I needed 16 A-levels, a slide rule, calculator and a box of headache tablets.
I had a friend who owned a GPz550, we had a fiddle. Two heads are better than one, besides he had brought the beer over. 11.30pm on a freezing evening we changed over the earthing strap, cleaned various electrical connectors and the fuses. The bike started and ran perfectly...
Next day, Saturday loomed sunny, clear and very cold. My dad came over to the garage to tinker with his Triumph 650. I wheeled the GPz out, fuel tap on, ignition on, idle lever fully forward, stabbed the start button and she warmed up to a fast idle as I sat on the beast and beamed at my dad. You're on fire, he bellowed, looking down where my crotch was obscured by plumes of smoke curling up between the seat and tank joint.
I stopped the motor and the fumes died a death. I leapt off the bike onto the grass, my jeans looked like they had been shot by Davy Crockett’s musket. My dad had a funny grin on his face. The fire was caused by my so-called mate removing the fuse box and replacing it so that when there was any weight on the non standard seat it squashed the lot and shorted everything out.
The bike still remained troublesome so it was dealer time. £70 later, no fault found. Riding home I was nearly crunched when the motor cut out halfway around a roundabout. It took two hours to do 15 miles. Next day the bike ran perfectly. On the way back from work, as I hit 6500rpm, accelerating hard, the motor coughs and dies. I tried to catch the motor as I change down through the box; it finally catches on full throttle in first, the revs soar round to the redline. The force cranked my head back so far I swear it hit the grab rail, we shot off across the road to stop dead 20 yards later. God it put the wind up me and my work mates were rolling about in the road laughing.
With mounting desperation I tried another Kawasaki dealer (Heathfield Motorcycles). One used air flow meter later (£20 as opposed to £130 new) the bike was back on the road and better than ever before. I'd owned the bike for two years and liked it but found the complexity of it too much. I sold it for £1200 and had 48 calls.
Kim Lester