Note it only covers bikes 1984 to 1986, I don’t have this so can’t comment on it’s value. Other members have said it has more detail than the Haynes but there are some worrying errors with torque settings. Haven’t found a free copy online, this link is to wemoto.com shop and you can also find this (and others) on eBay etc.

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click here for eBay shop

An online parts supplier based in the Japan.  The most comprehensive online resource I have found because it includes all years, including 3rd gen bikes, and quickly identifies bikes from different locations – except Australia of course.

The schematic diagrams aren’t the largest and can’t be zoomed which makes it hard to view on mobile devices – on the computer it’s fine.  and although there is no dynamic schematic function The information is extremely comprehensive and shows superceded part numbers and their current replacement – brilliant.

Curiously I have never been able to get the site to translate consistently to English, for me it continually coverts to Russian!

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You would expect this to be a definitive online catalogue, however it only lists the ‘Ninja’ from 1984 to 1986. So I’m  pretty sure this only represents the US-built bikes built/assembled in Lincoln Nebraska.  You won’t find a GPz900R here!

Technically it is a good resource if you have these versions, however no dynamic mouse functions and the zoom/pan buttons for schematics is pretty clunky.  But you can download comprehensive pdf files including schematics and all of the matching part numbers – really nice feature.

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This is the *only* one online resource I have found (so far) that lists non-US bikes earlier than 1986, although strange that it doesn’t list 1991.  The format is excellent and although the schematics aren’t resizable the parts lists displays shows a photo of the actual part in many cases. Nice touch.

What is interesting is the 1985 schematics not only also show the US-schematic change in crankcase, pistons, head & cam cover but include frame numbers as well as the engine numbers for engines ZX900AE & ZX900AG.  Of course US schematic engine numbers only match with ZX900AE engine series.

As the frame number references go right back to 001 this suggests these schematics apply to A1 bikes as well.

So why does this site have US data, after all not even the official Kawasaki Europe site has these.  And there is a notable difference to the US ones I have found, these schematics ALSO show a transmission change for the bikes that is NOT shown in any US schematics.  What does this mean? No idea except nothing is ever simple!

It has a really nice feature where you have an image flyout when you roll your mouse over the schematic index.  These images can be quite small and the titles aren’t always the same from version to version.  For example the starter clutch isn’t always listed here!

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You would expect the official Kawasaki Europe site to be the comprehensive online catalogue, however like many others it only lists bikes from 1986 to 1993.  I understand that the bikes were not sold in Europe post 1993 but no idea why there are no listings for the A1 or A2.

The site offers a direct VIN entry.  But…..it doesn’t work for my Australian A8 even though this VIN decodes properly on other European IV Decoder sites.  So grain of salt here I think.

It does list the A10 & the A5A as both Firecracker Red OR Ebony and is one of the few sites to identify a UK version.  I note although the Ebony link returns parts diagrams (common for all A5) it does not return any specific part numbers, unlike the Firecracker Red option – so perhaps there is a connection between the A5A and different colours..

Schematics do have a dynamic mouse function, however I suggest using a different highlighting colour to GREEN would make it a little more obvious!

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An interesting online parts supplier based in the Netherlands specialising in parts for UK & European delivered bikes for just these listed years. 

Although the schematic zoom layout is a little quirky, you can open a large image.  It also shows the photos of many parts (brilliant) and uniquely offers the direct microfiche list scans of parts.  These are two very useful features so if your bike is one of these (especially UK owners) it’s a great resource.

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An online parts supplier *similar* to Impex, no idea why it doesn’t include some years. 

Select the year of your GPz and it provides the factory part diagrams, just click the part you need in the diagram to immediately get a price and a Kawasaki Part Number. As per Impex schematic diagrams aren’t huge and can’t be zoomed.

FYI showing the change in starter clutch design from 1992.

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Another European online parts supplier.  Nice setup as when you select a year it shows you visually the different regional markets (eg. UK) as well as the different color schemes available in each market.

At the intro page the schematics index has a flyout which makes locating parts much easier, the schematics have a dynamic mouse feature and are presented in a portrait layout.  Again a useful site if your version is listed.

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May 2021 Update: this is the most complete online reference I have sourced so far (however not used).

As per other sites choose your Year first and it will present a GPz900R in the list of motorcycles to choose from.

A nicely formatted site with the ability to open (and download) a larger schematic (~800×1000) however no dynamic mouse linking.  All parts seem to get a price, however when you try to Ádd to Cart’ or click directly on anything unobtanium the site reports that you need to get in touch first.

Another benefit of this database (compared to the others) it not only shows the current part number but any superceded ones as well.  This is really useful for our local bikes to correctly identify things that have changed over time or might be different to European bikes – eg mirrors.

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May 2021 Update: during analysis of paint colours I discovered that these schematics (also used by Coastal) are strangely missing some (not all) PN for the ebony/gray A8.  By cross-checking PN I have identified another local reference (mattjonesmotorcycles.com.au) that has this missing information.  Obscure but still a data inconsistency.

However these folks have been used and suggested by Mark.N.  From the Kawasaki page (link below) you select a year from 86 to 91 and a link to the GPz for that year will show up.  A nice format with zoomable schematics and dynamically linked mouse, so as you roll over the schematics it highlights the part in the schematic and the details list.

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May 2021 Update: during analysis of paint colours I discovered that these schematics (also used by Coastal) are strangely missing some (not all) PN for the ebony/gray A8.  By cross-checking PN I have identified another local reference (mattjonesmotorcycles.com.au) that has this missing information.  Obscure but still a data inconsistency.

Another site that looks like it uses the same data as Elliot Brothers.  From the Kawasaki page (link below) you select a year from 86 to 91 and a link to the GPz for that year will show up.  A nice format with zoomable schematics and dynamically linked mouse, so as you roll over the schematics it highlights the part in the schematic and the details list.

A minor site glitch is searching by Part Number.  If you use the top level [SEARCH BOX] it works fine or from the Part Finder link there is another [SEARCH BOX] that also works fine. The glitch is when you are in the Schematics pages there is a third [SEARCH BOX] that doesn’t work at all, despite the PN clearly being in this models parts lists.  Just something to watch out for.

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Note: There must be a question as to whether this is the US (Lincoln) bike data, as the versions only match US production, there is no data for any other models, and the bike is referred to as ‘Ninja’.  

Note you have to search for ‘ZX900’, as ‘GPz900R’ returns no match!  A decent site, if you roll your mouse over the schematic it will show you the details for that part.  As mentioned this schenmatic is showing covers as US, Ca or Cn only, the emissions port head was ONLY used in the US (unti +2000 in Japan/Malaysia!)

Again this suggests that the data is for US bikes, and although a lot of parts would be the same there were many minor differences (eg. pegs).  Unfortunately without a definitive Aussie A1/A2 reference the validity of this schematic for Aussie bikes is unconfirmed.

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Amazing selection (Feb 2021 over 2,400) of new GPz900R parts from Japan. Not cheap.

Nice selection of new GPz900R parts that can filtered by the version of your bike.  Have an Aussie version site, may hove other versions based on your location.

A Danish company that has a really nice selection of new GPz900R parts including brake rotors, flashers, gaskets, etc.

Yep we all know about eBay and here’s a Japanese equivalent that often has lots of amazing and affordable GPz900R parts from Japan.  Pretty confusing as there are lots of different shipping & processing fees that apply.

Miraculously I purchased a NIB deep contour (drops me by 40mm) seat for my GPz900r off Gumtree.  The box shows it was from Japan, and working backwards brought me to this website.  They have an online shop (Google translates pretty well and I have contacted them by email to see if they ship internationally.

These are manufactured in Germany, and I have emailed them in Feb 2021 and they have replied (so NOT physically confirmed) that they fit under the OEM fairings of the bike.

Hi Adrian, Yes all of them confirmed.

Mit freundlichen Grüßen / Best regards

Auri Huesmann

www.cobraexhaust.de

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Carbon fibre, I’m not joking.  Wow – 2.9kgs fo the rear?  Wow again.  Well they need to be red for my A8, and I might as well get the ceramic bearings.  Only £2,755.83……not counting shipping from the UK to Australia!

Or for about the same cost you can get magnesium OZ Racing rims from Japan.

This is a photo of a magnesium Dynamag which IMHO looks more original.

Sean J. also recently (Apr 2021) found a set of 16/16 Mavic rims that came off an A1, however given the unusual sizes these were probably for a GPz1000RX.  If available in A8 sizes the design would match quite well MHO.

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I’ve seen some kits from China and others charging 2-3x as much for a stainless steel kit.  This is a very fair price IMHO and look waaay better than the hardware store bolts that I use. Grin.

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Yup, you can even upgrade the standard 4-pot brakes on your A7-A10 to the 6-pot versions used on the later Japanese bikes.  Not sure they will stop you better nor convinced that adding more un-sprung weight is a good idea – but they look fancy!  As per the eBay listing I think these will become rarer and rarer.

Note that these are not interchangeable with the single piston brakes used on the original A1-A6 front end.

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This is a really affordable (AU$99) temperature sensor kit that can even work as a low oil pressure alarm.  Sensors are as simple to install as adding a washer. Aussie company as well!

Phillip from Engine Guard (whose brother owns two GPz900R’s!) recommended adding an LED as he thought it unlikely you would ever hear the warning buzzer when riding. And I reckon he would be right!

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The OEM petcock isn’t considered great, however A8 bikes have a different tank and a different petcock part number. Note that there is only an a newer common petcock from Kawasaki.  It is absolutely NOT RECOMMENDED to be a cheapskate with this part – a leaking tap can hydro-lock your bike.

Many owners recommend US company Pingel, I haven’t found an Australian supplier.  This is to a UK store that actually only lists the GPz750, however it is reported to be the right one including the required backing plate.  There are many different orientations available, I’ll try and get a owner installed image.

Apr 2021 price look quite reasonable at around AU$160 from eBay (US) when you consider the direct replacement from the GPzone is AU$150.

GPzone replacement – not shipping internationally (Apr 2021)

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The OEM windshield is polycarbonate.  One of the negatives of the blazing sunshine we have in Australia is degradation of any clear plastics, no matter what material they yellow over time.  For my A8 screen this can be mostly polished out (annually), the technique is exactly the same used to clean up our yellowing plastic car headlights!  Almost any good polish works with decent elbow grease, Google ‘toothpaste’ for the really cheap solution!

However my issue goes deeper than this, literally.

The polycarb has internal ‘çrazing’ that means fine micro-cracks in the material that significantly reduces clarity under some light conditions & direction.  Rare but it’s there.  I would love to replace the screen but although there are many aftermarket companies (including several in Oz) offering many alternatives(tinted, race versions) they all use acrylic.

I do use my screen when riding.  If our old backs let us tuck down behind it it works surprisingly well when it’s cold & raining and is especially beneficial when crossing paths with a double-b semi-trailer.  Which also have a nasty habit of chucking up rocks.  Although I do admit my scariest moment was actua llywith a very low-flying parrot, I really did flinch expecting contact.

I realise it’s completely personal choice but I’m not a fan of acrylic winshields (why none are listed here) and I have not found a polycarb alternative.  

Superceded Parts

It looks like the original screen was replaced, at least for 2nd gen bikes.

*US schematics for 84-86 list 39154-1091

If the alternator goes you can replace or rebuild.

Replace with another

When purchasing a second-hand unit you can check that the plug is still attached to the lead BUT due to the buried plug location it is impossible to simply replace the alternator. I ended up buying one without the plug and just spliced it in.  I recall it being quite fiddly to align everything up and get it back into place – as usual patience and perseverance are the key traits.

Sep 2020: was quoted AU$165 for a second-hand unit from a local wrecker. I don’t recall my unit being that much, IMHO those numbers are probably spent rebuilding the old one.

Replace with ZRX

Apparently some US owners have used the ZRX1100 or 1200 units, obviously the same basic engine was used on later bikes (GPz1000RX) and it seems likely that the component was also shared.  Probably work double-checking part numbers.  At the end of the day newer is always better.

Rebuild

Here is some technical info from www.electronicamotos.com.ar for those considering rebuilding:

TECHNICAL ISSUE DETAILS
This Kawasaki model uses a Nippon-Denso car-type alternator that is mounted behind the cylinder block. Inside this alternator there is a field rotor with copper slip rings on which carbon brushes run. Around the rotor you will find the stator and in the front of the housing are the built in rectifier bridge and the electronic voltage regulator.

Common faults:

FAULT 1: OVERCHARGING THE BATTERY.  This is usually caused by (1) a bad internal voltage regulator or (2) a bad electrical connection somewhere on the bike in the lead that provides battery voltage feedback to the internal voltage regulator (the voltage sensing wire) The replacement voltage regulator is our part# ESR025. This unit replaces the OEM unit even though it looks different. To find the bad connection to the voltage sensing wire you need to look at the leads coming from the alternator. There is one large diameter lead, usually RED, that is the output from the alternator to the battery. The thinner lead is the sensing wire for the regulator. Use a multimeter to measure the voltage on this lead to ground. It should be close to the battery voltage with the bike running (around 14Vdc). If you see a substantial difference (say: battery voltage 17Vdc, sensing lead 14Vdc)you should look for a bad connection somewhere between the battery and this sensing lead. Inspect all connections, the ignition switch, use spray contact cleaner on everything. Spend some time and you will probably find a bad connection somewhere. Fixing this connection should fix your overcharging issue.

FAULT 2: NO OR LOW BATTERY CHARGING. This can be caused by a bad internal voltage regulator inside the alternator, or by a bad rectifier module. A bad voltage regulator sometimes is caused by a shorted out field rotor that is drawing too much current from the voltage regulator. Inspect the rotor resistance between the slip rings which should be 3.3-4.0 Ohms. Another cause could be bad connections between the alternator output and the battery terminals. Check all connections and see if this fixes the issue.

Brush Set

Here is a link to a replacement alternator brush set.

Rectifier

Here is a link to a video on replacing the old rectifier

However you can also use filed broom handle or ground bolt, etc. as long as the measurement across the flats is 22mm for 1st gen bikes. 2nd gen bikes had bigger forks so apparently the measurement is 27mm.  One of the best solutions is to use a tube spanner – apparently the OEM plug spanner is a perfect fit.  Recently a forum member bought a 7£ set of tube spanners off Amazon and because they can be nested worked perfectly!

You used to be able to get just one fork serviced, but recently it seems like the only option is to service both at the same time.

Which makes sense, and $AU330 is very reasonable compared to the effort of doing it yourself.

However I was surprised to get the bike back with the original badly cracked dust seals – I understood that that all seals would be replaced. It makes absolutely no sense to me to not replace these when the entire forks are dis-assembled.

I recalled previously asking another Kawasaki service centre who assured me that all seals would be replaced, however I was told that new service kits do not always contain the dust seals. Hmm…..OK. So something to check IMHO!

Anyway my local Kawasaki service centre was very reasonable and put in new dust seals for no extra charge. Greatly appreciated.

Note the GP Zone website describes leaking oil, I’m 90% sure mine was leaking coolant. Either way purchasing the seal kit directly from GP Zone makes this a relatively painless repair, I see you can even buy a rebuilt waterpump (£199) if you simply wanted to plug another in.