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.).