Faults:

Cam chain tensioner (these things die easily; mine went shortly after I bought it)

Had to replace the cush-drive along with it.

Poorly serviced (fork oil, bearings, brake fluid, master cylinder...)...

...and poorly treated (crash damage, square rear tyre from burnouts) by the previous owner (s).

Watch for chrome pitting around the lower inside of the fork legs.

Bake brake drags very slightly (not sure why yet).

It's spent most of its time in pieces making up for typical servicing requirements.

The previous owner dropped it while 'washing it' and cracked the side cover. I'd suggest some frame sliders to restrict this happening again. Motovationusa.com do some decent ones.

General Comments:

Handles great when the tyres, wheel bearings and cush-drive aren't knackered.

But it could do with braided lines, as the rubber hoses are getting quite spongy at 15-16 years old.

Odd thing about it is that the chain is measured by how close it can get to the swing arm without a rider (or so the manual says).

The ZXR400 is a more responsible step up from a smaller bike in place of a 600+ (believe me I know). But the power out of corners is lacking over 100km/h, so the novelty of owning a 400 wears off pretty quickly.

In comparison to other larger bikes I've ridden, (Aprilia SL1000 Falco, Kawasaki ZR750f) the low seat height and weight makes riding easier; all you have to do is throw your body in one direction and the little Kawasaki actually responds (I'm 65kgs, so it means a lot to me).

Still, the Aprilia out classes it with braking quality (Brembo) and a general feeling of stability and steering responsiveness (Ohlins and it's Italian). Not that it equates to anything greater than the 400 in regard to cornering speed, it just feels easier to ride. Such a pity it's so heavy and large (he says, hoping Cagiva releases a Mito 500 or 650).

Faults:

One crash (oops).

Alternator coils melted.

General Comments:

Fun fun fun.

Shockingly fast little bike. No go below 8000rpm, followed by the most amazing acceleration and noise up to 15000rpm.

Razor sharp handling; remember this bike has a steeper steering angle than an R6. The bike will go round corners faster than you can imagine. I never got to it's limits on the road.

The most uncomfortable bike ever I think. The rear shock is rock hard, and the seat very thin. The riding position is bum up, head down and quite hard on your wrists. After 10 hours and 500 miles riding, I could hardly walk the next day.

It's bigger than every other 400, so if you are tall and want a 400 sports bike to start with it's ideal, but budget for a replacement shock.

Also very pretty, looks a lot like a ZX7R and can be mistaken for it due to the size of the 400. Voted as one of the top 100 most beautiful bikes ever (14th I think)

Faults:

Rust on the tank.

Rear shock needs a rebuild.

Carbs need a tune.

General Comments:

Add to the fact that it has the first incarnation of the KBATL "Kawasaki back torque limiter" now known as slipper clutch.

A hugely proportion bike, side by side with an 06 R6 and CBR600RR, the ZXR blends in size, and only those with a very keen eye for detail will notice that it's only a 400cc (not to mention those who know a lot about Ninjas and the 400 mark sticker on its tail).

Here's a personal hands on experience upon acquiring this baby ninja just 3 months ago:

The ZXR I own is not my first bike. I owned a couple of 400s way back, but this is my first time back riding a true sports motorcycle.

The first sports bike I ride was a total mess. I didn't have much experience at that time, which led to a very painful accident. After my recovery, I rode a semi sports naked motorcycle and got back to basics in road riding.

After a couple of years riding experience with my street bike, I came to the point of moving on and upgrading to a type of bike I once loved and almost took my life with, a sports motorcycle.

Choices were, CBR400RR gull arm, GSXR400, and the Kawasaki ZX4 (ZXR). There's something with the Kawasaki that made me decide to look for one. I was very fortunate that enough after 4 months of searching, I saw a nice lookin ZX4. After a week, I bought the bike without even checking much due to excitement (lesson learned). All I know (from what the previous owner told me) is that the speedo drive is the only thing that ain't working. But later found out that a bit of stuff needs to be done, but fortunately no major engines problems have occurred.

Here's what I've sorted out, the bike has been stalled for a couple of weeks, which means that it has already accumulated rust on the tank down to the carbs. The 3rd cylinder ain't firing due to a clog, one dead spark plug, one of the downpipes bolt thread is loose so it leaks, and rear shock needs a rebuild. The only good stuff here is the pair of almost new Bridgestone tires. I was frustrated and disappointed, but that didn't stop me from bringing her back to race condition.

So I had it fixed with the help of my dear mechanic, electroplated my tank, cleaned my carbs (lots of rust), replaced a couple of o-rings on the carbs, and we've just found out that one of the jets fell, so we put it back, we changed the oil, have it balanced/sync and lastly I put in a new speedo drive.

Now, it's testing time. Very unfortunate that the weather wasn't cooperating. I was forced to take her home, and said to myself "maybe next time", that was Saturday and was hoping that by next morning it would be fine.

The next morning, I guess my prayers were answered coz the weather was so perfect, so I took her for a spin through the countryside, which involves a lot of uphills, downhills and tight turns. I noticed immediately that it feels very different than the first time I rode her. She is SO damn fast for a 400, accelerates like a 600, especially when you reach above 8K on your tach, and starts to scream down until 14K redline.

Not to mention that she is so stable in corners, as if she wants to corner forever. So for four straight hours, I rode her from medium speeds down to bansai speeds. I never noticed that I'd been turning corners way faster than I used to be (due to its lightness), the stock brakes did their job (but it will probably be much better with aftermarket pads and steel braids) and the front feels so planted.

My hard work paid off, and she rewarded me with satisfaction and a huge grin in my face. No doubt this bike won't leave you behind against the latest higher displacement sportsbikes.

Other possible mods you can do on a ZXR4:

I've heard that this bike with a tuned full system exhaust pipe and dyno tuned adds 10 hp from stock, so that's 72hp. And for pure racers who go for the big bore process can attain 80+hp.. Others have success in slipping in a Fireblade engine (that's serious power), and replacing the front and rear suspension with the parts from an 03 ZX6 (along with the wheels, brakes.. etc.).

Faults:

The only thing is that the clutch had worn a few weeks after purchase, so a new one of those was at hand for all together £450.

General Comments:

Lacks low down torque, but after 8000rpm boosts itself up to a blistering pace, all the way up to 13000rpm.

A comfy ride until 110mph.

Snappy and electric is the only way to describe the handling.

Faults:

My head gasket blew at 11,000 miles.

The clutch cable snapped.

The rear shock lost its rebound damping, requiring a new shock to be fitted.

I also had numerous problems starting the bike when the engine was hot, requiring me to have to bump start it. This problem was solved with a new set of spark plugs and the carburetors being balanced.

General Comments:

This motorcycle is great as an introduction to sports bikes. Especially if you have just passed your test or aren't very tall.

The engine loves and needs to be revved. You won't see much action below 10,000 revs. It will definitely keep your left foot active.

As for the handling, it's very good on smooth roads. But if the road has any bumps on it, you'll soon find out, as the rear shock is very hard.

The bike's engine will soon feel rough if it isn't serviced according to the manual.

As for tyre wear, I get between 4000 and 7000 miles a pair.