Tech Tips

Tech Tips

General (applies to all/most models):

All models.

Slipper Clutch A little known fact about ZXRs and ZX7Rs is that all models from 1989 to 2003 are equipped with Slipper Clutches. The reason most people don't know is that Kawasaki set them with minimal slip at the factory. Here are the Racekit tips that allow you to activate them: Tuning the Slipper Clutch.

Ride Height front and rear. Dropping the forks and adjusting rear Ride Height. A lot of people have asked me how to drop the forks or change the rear ride height so here's my step by step guide to Dropping the forks and adjusting rear Ride Height.

Mini Indicators. You can shorten the rear indicator stalks making the tail look better at no cost. Simply diconnect the rear indicators wires (in the tail unit), unbolt the indicators. The stalks separate from the indicators, so take them off, fit the indicators back on and mount the stalks on the inside (under the tailpiece) and reconnect the wires. Easily done and looks good. I have done it to my ZXR and I'll soon do that to the ZX7R

Brake Tip. Here's a tip to get a better feel for the brakes and have to squeeze the lever less to get the same braking power. Loosen the two allen bolts clamping the front brake master cylinder assembly to the handlebar. Slide the whole assemly along the handlebar away from the switches and towards the fork tube until it can go no further. Tighten the allen bolts. Like this you will have better leverage, better reach of the lever and much increased levels of feel. Now go and try it out and then start wondering why they don't do it before they sell you the bike.

520 Chain Conversion I have just changed the chain on my K1 from the stock 530 to a 520 (later P and N models use a 525). The difference is that basically chain and sprockets are narrower hence lighter. A 520 chain is supposed to last less than the stock ones, but just go for a good quality chain and keep an eye on it and you should be OK. My previous 530 chain had snapped at the sideplates (not good quality!). The sideplates on my 520 are actually thicker than those of my old 530.
A WORD OF WARNING. After installing the chain I noticed it was not quite straight, but pulling slightly to the left in the middle of the top run (looking from behind). The reason for this was the swingarm guard. This piece of plastic has a raised chain guide which is fine for a 530 chain, but causes the 520 to be slightly out of line. I am sure that lots of people have done the conversion without noticing this and for all I know it may have had no adverse effects. However I decided to make the guide narrower by cutting it from the outside in to allow the chain to sit OK. I took the swingarm off and used a dremel tool on the guide and now the chain is dead straight
I presume this might happen with P and N models too, though probably to a much lesser degree as their stock chain is 525.
Cush Drive These wear out and only cost Ł25 (GBP) from Kawasaki so do yourself a favour and replace it when worn. To check if yours is worn do the following:
With the bike off stick your fingers through the holes of the rear sprocket and try to rotate it backwards and forwards. If you can feel any play in this replace the cush drive!

Race Airboxes An explanation of what a race airbox is and an outline of what is involved in fitting one to your bike.

Lifting the bike securely to remove the swingarm (91-03 models + notes for 89-90) I have heard of many methods that people use to lift the bike to remove the swingarm, but a lot of these seem to put the bike in a very unstable position
I have found a cheap way to do it that leaves the bike very steady for you to work on. This method relies on using my trusty NWS Ulti-pro stand in a way that it wasn't quite designed for.
Normally this stand lifts the bike hooking up to the swingarm holes, but this is no good if you want to remove the swingarm. So I removed the footpegs and levers from the footpeg hanger plates. took two pieces of alluminium and made round holes in them of about 15mm ID. Then I put the supporting spikes of the stand through each hole and wound some duck tape around the tip of the spikes to protect the footpeg hangers and to prevent my "adapters" from coming off. I then assembled the stand and put the spikes through the triangular hole in the foopeg hangers (I put some duck tape over the hangers to prevent scratching). You can use large washers to do the job of these adaptors if you can find them.
This way I was able to lif the bike securely whilst my adaptors prevented the spikes from going in too far and kept the bike very steady. I would still recommend loosening and tightening all the big bolts with the bike safely on the ground, but with this method you can safely apply a fair amount of force.
For 89-90 H models The hangers are different for these models, however it should be possible to fabricate a couple of brackets with suitable holes (as well as the two holes described above) that could bolt on where the foopeg hangers usually are. This should allow lifting of the bike in much the same way

Ken's Tips Click here to go to the digest of Kenneth Waters' excellent tips on ZXRs and ZX7Rs summarised from his posts to the ZX7 Owners Club

Some tips offered by Tom Sitt from Canada

Oil leaks around the slave cylinder area: These are usually due to the clutch push rod wearing and engine oil weeping out. The rod is made of aluminum and it wears out rather quickly. You can actually see the wear at where it rubs against the seal. Funny how aluminum wears out against rubber. Try changing the rod first. If it still leaks than you will have to change the seal. If you could get someone to fabricate a rod out of steel, it would be a lot more durable, especially against stronger clutch springs. Also the slave cylinder itself can leak 'brake' fluid. Rebuilding is an option but check the bore of the assembly for corrosion from infrequent flushes as complete replacement may be necessary instead of rebuilding.

Oil leak around the front sprocket seal: Since this seal and the push rod seal have to be installed with the cover removed, you should always change both at the same time. Those seals are relatively inexpensive and you will also need the paper gasket for the cover itself. I just used RTV myself but I imagine the cover will be rather difficult to remove next time. Also since you have to remove the water pump, check the weep hole to see if it is leaking and check for play or roughness in the pump bearing itself.

Rubber damper in the valve cover: The timing chain rubber damper can break up into little pieces and if it does it will end up clogging up the oil pickup. Next time you guys do an oil change watch for rubber bits. That is usually what it is.
I cleaned up the pieces and installed a new oil pump pickup(pretty cheap) and reinstalled a new damper.

Clutch back torque limiter springs: These can be a weak point (and should be checked fairly regularly A.M.). They can break into many pieces hopefully staying within the clutch basket and if one of the pieces lands right, you may not be able to disengage the clutch. If this happens on the road you may be stranded.
Try engaging and disengaging the clutch to dislodge the broken piece and get home ASAP!

91-92 models.

Improve the rear suspension. Fit a shock linkage from a '93 to '95 L model (not the M though) or a '96 on P model. See K1 suspension Mods for more info (applies to J models too).

91-92 K model Specific tips:

Fitting a Race Airbox to a ZXR750R Find out what is involved in fitting a race airbox to a K or J model (also useful for other models)

Coils Relocation This is particularly useful when fitting a Race Airbox

Coolant bottle

On this bike removing the seat unit (one piece item) with the coolant bottle in the way is a very tricky job. for this reason I thoroughly recommend ditching the stock coolant bottle and replacing it with a '98/2000 R1 item (you will also need the cap which is sold separately). The latter fits beautifully in front of the radiator on the right hand side and can be secured to the rad with cable ties. You will also need the bottle cap which is sold separately. Now you can remove the tail unit without risking breaking it or scratching the tank and access to the rear brake fluid reservoir is greatly improved.

Rearsets If you fit rearsets or jack up plates you will probably have to move the shock's remote reservoir as far back as it goes to avoid clouting it with your heel.

Jetting the ZXR-R by Ken Waters.

91-95 models.

Upgrade your brakes to 6 pot calipers!!! The step by step guide to upgrading your J, K, L and M model to 6 pot brakes. Upgrade Your brakes to 6 pots calipers!!!.

Upgrade your rear brake and get rid of the torque arm Details to upgrading your rear brake to a lighter unit and getting rid of the torque arm. Upgrade your rear brake.

750/900 Conversion Guide for '91 to '95 ZXR750s This conversion guide (based around fitting a ZX9R-B engine in a ZXR frame) is based on Pete Pham's guide, though a number of people have also contributed with information and pictures. Thanks to all.

Shut Off Couplers. Fit "shut off" fuel couplers on the two fuel lines going from the tank to the fuel tap. You need two couplers for 8mm fuel lines. That way when you want to remove the tank you don't have to remove the fuel tap too.

Upgrading J and L models to P model forks and brakes.
Information kindly provided By Bill Low.
Fork upgrade info.

93-95 models.

CV Carb Tuning tips for L models from Riccardo (Italy)

93-03 models.

Float bowl vent mod in pictures. Kindly provided by Rory (aka Rozz) here's a step by step illustrated guide to performing Ken's famous Float Bowl vent mod.

96-03 models:

Setup The ZX7R comes with a very conservative setup which makes it steer slowly. you can sharpen it no end by altering the ride height. Lower it at the front and increase it at the back. See my Suspension Setup for reference or my guide to Dropping the forks and adjusting rear Ride Height. The bike will steer miles quicker without any major effect on stability.

Fit a rear Hugger. Unless you are lucky enough to live where it never rains you WILL be glad you did.

Rearsets Fit some rearsets, better if adjustable. The ZX7R's stock pegs are too far forwards and a little low. I got adjustable Jack up plates from Ray Stringer for Ł110. They move the pegs 2 to 4cm back and 2 to 4cm up.

Coolant bottleMany 96-on ZX7R suffer coolant bottle failure. they crack at the mounts and start spewing coolant over your exhaust and potentially your rear tyre (coolant is very very slippery). This has happened to me and I have replaced the tank with a Kawasaki spare. Interestingly the new tank has been modified with metal inserts in the problem areas to prevent cracking so hopefully it should last longer than the original.
TIP FROM Curtis (2 May 2004):
I bought a '97 used and it started leaking coolant. it was cracked at the bottom mount. So I bought a used one, and the SAME thing happened early the next season. So I siliconed mine up and hoped for the best. But when I went to install it I noticed that there is a bit of strain on the bottom, the tank wants to 'bend out' at the bottom, but when you tighten it up it's 'pulled' in.
What I did is not use the little plastic bushing on the bottom and just it sort of 'sit' there on the fully tightened bolt, so it's not 'pulled' in toward the bike.
Hasn't failed yet!