Kawasaki GPz900R (1989)

Actually I had two of these 1989 models in a row (the second machine is the one pictured). The first one I only had a few months, before writing it (and very nearly myself) off in spectacular fashion. If you would like to be regaled with that tale, click here.

Anyway, after recovering from my injuries, I was still so impressed with the GPz that after a short search I managed to find another one in top condition, for $1000 less than my first GPz! Although I did have to fork out for that new 'Formula 1' exhaust, which turned out to be a well-configured 4-2-1 system. The second machine also had a 'Vance & Hines' ignition advancer. So all things considered, my second GPz had more zip than the first.

This second GPz I had for nigh-on 7 years, and sold it in late 2003 to get the Katana. But what an excellent amount of motorcycle you get for your dollar with these GPz900s: power, handling, reliability, great styling... in short, THE LOT.

So why did I sell it? Well for one thing, GPzs are great bikes but I'm a man who likes to tinker and the bike was just a bit too reliable and boring for me in the end. And for another, the starter clutch (which is buried — and I mean BURIED — in the internals of the engine) was bascially flogged to death. Fixing this was going to require more than a little tinkering — as a perusal of Floyd's account of his GPz900 engine rebuild will show.

But more to the point, for years I had wanted another GS Suzuki. So I sold the GPz for a fair price and went out and found the Katana. But GPz900s will always be well-respected by me. They are getting hard to find now with low mileage, but if you find one that's been looked after you won't find better motorcycling value anywhere.

GPz900R vs. Katana 1100

An interesting and even-handed review of the GPz900R versus the Katana 1100 at Visordown.

Mike's GPz900 tips...

• Not much goes wrong with GPz900's. Keep the oil clean (change it every 3000km, filter every 6000), and don't forget it has two drain plugs underneath (one is kind of behind a rubber oil hose).
• Starter clutches can give up the ghost after high kms. They are a pain to fix because you will need to remove the engine and split the cases.
• When parked on the side-stand, #1 spark plug recess (ie. the plug on the left-hand side of the engine) can fill with rainwater because the cam-chain ridge won't let the water run away. The result is misfiring on that cylinder — spark plugs submerged in water tend not to work too well! So take care to keep it clean and dry, and you might even want to try a smudge of silicon around the rubber seal.
• Checking the oil level can be a bit of a worry at first, because the level seems so erratic. You check it one day, and it's full; check it after the next ride, and it can appear very low. Then later on it's OK again. Don't worry, they ALL do this, sir. No really, they do. I'm just guessing here, but it might be related to air pockets in the oil ways, or something like that.
• If your steering develops a front-end shake while decelerating, it will usually either be
  (i) the front tyre pressure is too low, or
  (ii) the front tyre is worn. Often you can see the 'scalloping' of the tread into high and low spots, which is what sets off the shaking. Time to replace the tyre!
• Is your camchain rattling? Don't worry, these are the easiest camchains in the world to replace, thanks to their brilliant accessibility there on the left-hand side of the engine. You don't even need to split the chain; it can be installed as a complete loop simply by removing the rocker cover, the camchain tensioner, the camshafts, and the left-hand crank-end cover. Oh that they were all this easy! Mind you, this piece of Kawasaki design brilliance is effectively neutered by the world's most inaccessible starter clutch (see above).
• The rear shock damping goes off when the oil in there gets old. But it's easy to put right: just remove the shock, unscrew the air pressure hose that goes into it, and tip out the old oil into a measuring cup. Then re-introduce that same amount of fresh oil (I used a 10W viscosity) into the shock with a syringe. It will take about 200ml of oil, if I remember correctly.
• Being a product of the innovative 80's, all the A1-A6 GPz900's (ie. 1984-1989 models) will have antidive units on the front forks. Even after 1/4 of a century, the jury is still out as to whether antidive is worth retaining or not. If you ditch it, get better fork springs. If you keep it, it pays to periodically dismantle the antidive units and make sure the little piston etc. isn't seized up. (The little circlip in there can get rusty and lead to things getting stuck.)
• If you haven't already made the upgrade, ditch the stock camchain tensioner for a ZZR-1100 item. That's because the ZZR jobbies are 'ratcheted', ie. designed to avoid 'backing out' under sudden closing of the throttle, which can lead to jumped camshaft sprocket teeth and thus valves crashing into pistons, etc.
• After some basic service info. and specifications for your GPz900? Go to the A3-A6 GPz900R page on 'Motorbikespecs'.
• If you own a GPz900R, the GPz Zone is the place you want to go for parts, advice, and information.
• And finally, you really should read the Classic Bike 'dossier' on the GPz900, which you can download as a PDF here. Well, you could download it until some bean counters somewhere decided to turn the Classic Bike site into what is essentially a useless banner. Just email me if you would like a copy of the Dossier.

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Anyway here's a couple of photos of the old girl just before I sold her:

Update (10^th Nov. 2006): Well today I went off to 'Two Wheel Wreckers' here in Perth, looking for bits for my GS1000S, when a black GPz900 in the front yard caught my eye. I wandered over and — you've guessed it — it was my old bike. Almost three years to the day since I sold her. So I got chatting with one of the fellas who works at the wreckers, and no, it hadn't been pranged. Just brought in with seized brakes and tell-tale signs of moronic neglect. For example, what do you do when you manage to break the lock on the tank filler cap? You gaffer-tape it shut, of course.

A sad and dismal end for a great motorcycle. In fact, I almost feel guilty for selling it into the hands of the incompetent...

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Alastair's GPz900R...

March 2009: My mate Alastair has just picked up this GPz900R — registered and running — for a piddling $1500! The engine is sweet, but a number of mis-matched bolts and screws, and other minor crimes, betray a history of 'well-meaning' previous owners. Lucky for Alastair he enjoys spannering. There is also the major crime of that exhaust system; you can't go over the slightest speed-bump without it bottoming out. Ridiculous!

And here (below) we have a recent (Sept. 2009) side shot. As you can see, the GPz900R is a reasonably complicated but very-well engineered thing! Note:

1. K&N pod filters. These have taken a bit of work to set up properly, but as usual perseverance has paid off.
2. Pleated filter for the crankcase vent (it used to go into the airbox, which has now been shelved).
3. Nice 2nd-hand Nexxus stainless-steel exhaust system, sourced from the UK. A vast improvement on the previous barbarian system (see photo above).
4. Manual camchain tensioner — a common modification.
5. Clean oil in the sight-glass window!

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