Welcome aboard -

Here are some tips that you may find helpful:

Many newbies and not so newbies run into or issues with their bikes which could be easily avoided with a little preparation or information. Here are a couple recommendations that I hope you will find useful.

Before riding your KZ you should take a little time to become familiar with it. Simple things like checking the oil, tire pressures, etc. are explained in the Kawasaki Owner's Manual. If you bike didn't come with one (they normally are in a little holder on the bottom of the seat) you can usually find one on eBay - be sure to get one for your exact year/model.


MANUAL

You really should consider buying the Kawasaki Factory Service Manual for your bike. The factory service manual provides instructions on the various maintenance procedures and schedules for your bike, procedures for diagnosing problems, proper torque values for the various fasteners (VERY IMPORTANT), and insight into how each system on your bike works even if you are not repairing that system. Studying the manual before you attempt performing service on your bike will impart an understanding of the system you are working on which will increase the odds of success.

The manuals usually are readily available for most models on eBay and other sources; but be sure to get one that has your specific year and model in it as there are differences between the various KZ650 models. I do not recommend Clymers, Haynes, or other aftermarket manuals as I have seen instances where they provide inaccurate advice. You may decide to use those to supplement the factory manual, but in my opinion they are not a suitable substitute. If you have trouble finding one for your model ask us to help.


TOOLS

WARNING! Do not even try to use Phillips screwdrivers on the Kawasaki cross head screws. Despite their appearance they are not Phillips screws. They are Japanese Industrial Standard (JIS) screws. The tips of Phillips screwdrivers are too long & pointed to allow the 4 blades of the screwdriver to properly engage the screws, so when you apply force the screw head slots will deform and look like crap. The fact is that Phillips screws were deliberately designed to have the screwdriver bit "cam out." This was done to prevent production line assembly from over-tightening, stripping, or breaking the screws. JIS screws do not have this problem. A proper fitting JIS bit can tighten a JIS screw to and beyond the torque spec without camming out. Here's the good news - you can easily modify standard Phillips screwdriver tips to fit the JIS screws.

I have ground down the tips of DeWalt #2 and DeWalt #3 Phillips to make them fit JIS screws. The large crosshead screws on the cases take modified #3 bits (or genuine #3 JIS bits). To modify the DeWalt bits you need to grind the very tip a little, then test fit, then grind a little more and test fit, etc. until the bit no longer "rocks" back and forth in the screwhead. Picture 1 below shows how a DeWalt #3 bit fits the case screws of my KZ650 after being ground properly. The #2 DeWalt bits can be modified the same way to fit smaller JIS screws. Pictures 2 and 3 below shows DeWalt #2 and #3 modified bits.

I did find a place that sells authentic JIS bits. They don't list the #3 bit, but if you contact them they can provide the #3 JIS bits even though they are not listed on the website. These folks were very easy to work with, and the authentic bits do work great. Here's their site:

www.rjrcooltools.com/shop_item_detail.cfm?subcat_ID=89

Pictures 4 & 5 below show a comparison between my home made modified bits with the authentic JIS bits, and picture 6 shows a comparison between Philips and JIS bit tips.

PICTURE 1

PICTURE 2

PICTURE 3

PICTURE 4

PICTURE 5

PICTURE 6





Before reaching for that wrench or ratchet consider the following. The bolts are steel, but your engine and front forks are aluminum. The bolts are much tougher than the aluminum and if over tightened will strip the aluminum threads. Although these can be repaired, preventing damage by applying proper torque will save you grief, time, and money. Tightening fasteners properly requires torque wrenches. Various vendors, including Snap-on, CDI, Sears, etc., market torque wrenches. The two most popular types are the bar type and micrometer type. Either will work, but the micrometer type is a bit easier to use, especially if you are tightening several fasteners with the same torque - such as cylinder head covers. You will need a torque wrench calibrated in INCH POUNDS for many of the bolts. You will also need a torque wrench calibrated in FOOT POUNDS for the larger bolts. Don't try to use the foot pounds wrench on the smaller bolts as it will not be sensitive enough at low torque settings to provide accurate torque. There are many fasteners that require low torque. These include such things as 6mm oil pan bolts, cylinder head cover bolts, etc. for which the torque in 61-78 inch pounds. These low torque bolts require a wrench that is accurate at low settings and this wrench should be graduated in inch pounds. In addition, there are numerous high torque fasteners such as the front axle nuts (51 - 65 foot pounds) or swing arm pivot shaft nuts (58 - 87 foot pounds). These require a wrench that is accurate at higher settings; this wrench should be graduated in foot pounds. Using the proper torque wrenches to correctly tighten fasteners will help prevent damage and contribute to a safe bike. The Kawasaki Service Manual will list the various torque specs for the bolts. I suggest you get the manual before buying the torque wrenches so you can decide which wrenches best meet the torque specs.

Consider buying a can of Kroil penetrating oil and use it to soak stubborn fasteners for a couple days before trying to loosen them. Remember, the original screws and bolts were installed on your bike when Jimmy Carter was President, so many of them may be hard to remove. Kroil can be bought online, at guns shows, and at some other venues.


MOTOR OIL
The ingredients in oils have changed over the years. For example, today's Castrol GTX (and pretty much all AUTOMOBILE oil) is not the same as it was in the 1980's. Back then it worked great in KZ bikes, but things have changed. Zinc and phosphorus additives (ZDDP), important to protect engine components from metal to metal contact, has been reduced since it’s been found to shorten catalytic converter life. Today’s auto oils contain about ½ the ZDDP they used to and different additives have been developed as substitutes. Unfortunately, some of these newer additives, in particular molybdenum disulfide, don’t get along with the wet clutches in our bikes. Newer oils, especially those labeled “Energy Conserving” (EC), which have a high quantity of friction reducing additives, should be avoided. These oils work fine in automobiles but there are better choices for motorcycles.

KZ bikes need oil which is suitable for wet clutches. That distinction was defined by the Japanese Engine Oil Standards Implementation Panel (JASO), and can be noted by oils that meet the "4T” (4 cycle) specification, MA (wet clutch) classification. These oils, which include various synthetic, semi-synthetic, and non-synthetic oils, are sold as specific motorcycle oils. Another type of oil which works well in our bikes is diesel engine oil. These oils are governed by the API (American Petroleum Institute) CI-4/CJ-4 spec and don’t contain clutch-damaging EC additives. You can even purchase Shell Rotella oil which holds a “JASO-MA” certification assuring it will get along well with your wet clutch. All of these newer oils have a reduced ZDDP level too (about 1/3 less than before instead of ½ like the auto oils) but the substitute additives get along better with our bikes needs than automotive oil. Oils that do not hold the JASO-MA rating have either failed the wet clutch test or have not been tested for use in engines with wet clutches. Good luck with your bike! Ed

I have a carb'd bike and I'm content with just one haha
The idea is to have a fun bike to ride that is 100% unique to me
All the swap parts are fairly straightforward but the engine will likely need some work to fit but I like the R1 cross plane sound and a cart kit for that engine is fairly cheap
It's wild how expensive a titled kz frame is though
Holding out for a barn find
I do have a few solid leads on zx10 front end parts tho and I'm going with the gs swingarm and dual shocks as well

NakedFun wrote:

Richie7 wrote: Yes, I plan on pressing out my sporty triple tree stem and transplant on the Zrx triple lower. What I'm mainly interested in knowing is how to make HD hub work in ZRX forks/brakes setup. Thank you for replying though.

Richie,

It is in the build thread, (Pages 17-21) but it will greatly depend on what front HD hub you are running. The hub I used is the 77-84 Narrow Dual Disc hub and then machined it to accept 47x25 roller bearings then used 1/4" spacers to get disc alignment proper. Then you still need to cut an inner bearing spacer and two outer bearing spacers. There are numerous factors you need to consider to safely adapt the front wheel.

"So the following hubs were used:

Front: 77-83 Harley Davidson Dual Disk Narrow Glide (FXR & FXH?) - I bored out the bearing pockets to 47mm to press in 47 x 25 x 12 sealed ball bearings and cut a new inner spacer to fit the 25mm front axle from a ZRX1100/1200. .250" spacers were made to get the disk spacing proper. The rotor spacers will need to be notched to fit the speedo drive collar. A custom made axle spacers.

Rear: 2000 + Wide Glide Aluminum "Spool" Hub - Dual Disk - Bearings swapped from a 52 x 25.4x12 to a 52x20x12 and new inner spacer made. A custom aluminum rear rotor adapter made along with a custom Cush drive using Ducati and Suzuki parts."

Cory

Cory,

I will go over the thread again and check out your specs/pics. But, knowing specifically which hub you used and that it has enough meat to bore out and accept ZRX bearings/axle is a huge help for me. I will probably end up re-lacing the stock sporty rear hub and use it in a stock swingarm paired with modern shocks. But that's also good to know for the rear hub option as I have been planing to do a modern dual shocks set up on Z1R or Z1000R someday. Thank you for sharing! I really like your build!

andyshear wrote: The front tire and rear tire are are both about 2 years old but the bike has been sitting for around a year or so also. I pumped up the tires to the bikes psi specs then I rode. Whenever it shakes at around 20mph it's pretty minuscule but whenever it gets around 50+ it feels crazy terrifying. No cupping in the tires because when I purchased them I only put about 600 miles on it before letting her sit.

So it looks like I will have to check out the wheel bearings. What's the best way to tell if they're bad or not?

If the bike sat in one spot for 2 years and the pressures were a bit low, they may have a bit of deformation causing a small flat spot, just a thought... Make sure you check the swingarm for play too..

andyshear wrote: Whenever I rise above 20mph or I let go of the handlebar the handlebars shake more than Beyoncé in the club. After a highway ride my hands feel like they have been gripping a vibrator on extreme settings. Any fixes you wonderful people may know of?

How old is the front tire, any cupping, uneven ware, out of balance, tire pressures, play in the front wheel bearings ..? Check steering head bearings and swingarm bushes, yes, bad swingarm bushes can effect the front too... Any one, or combination of the above can produce a wobble at the front...

More bits getting done:

The headlight ears and passenger peg carriers are satin powder coat,the grab bar and kick stand are gloss PC.The engine,coil and electrics mounts are Appliance "Epoxy" like the frame.I'm loving having a blast cabinet and my home PC kit! Swing arm is done to,four new bearings(2 is stock,lengthened 750 twin sleeve ,a grease nipple and new pivot bolt.

Hi I'm Chris ,
Just a one man shop ,currently I have 140 swingarms coming through the works not counting 17 bike builds that I need to pull finger on
Lucky I have a S1 at the shop so I did copy that swingarm and added a couple differ met things due to safety ...my Calfab swiinarm

s are the only ones (including Japan ) that at 2 stage heat treated and aged

S1 oil coolers,rear sets ,spondon race calipers also coming through the works

No eBay APP ID and/or Cert ID defined in Kunena configurationThanks for the comments guys. Definitely some food for thought. Based on some of the comments I may scale back on the build and get the bike running first the way it is now. Just don’t want to spend money on things like suspension, tyres etc only to have to change it later.

I’ll try to elaborate a bit on my thinking for some of the changes I want to make.

The wheels on these are 19F and 18R. 18x2.15 to be exact. What would be the fattest tyre I can fit on that rim? Seems to be a 120/130. If that looks decent I may keep it. Would certainly be the easiest solution for sure and I do quite like the spoke design of the enkei wheels. Widening the rim is an option too. I suppose the cost can be justified by comparing that to the cost of a different swingarm, chain conversion etc etc. The stock swingarm will need to be grinded a bit (it has some bracing) and then welded again to strengthen the bracing that will be ground away to clear a fatter rear tyre.

The rear wheel does look a little “tucked” in at the moment though. I’m guessing the only way to fix that is to change the swingarm. Is the KZ1000 ’79 shaft swingarm any longer? If the shaft is compatible with my motor then that would be an easy swap that fixes my length and wider wheel issues in one go.

As for the EFI. If the carbs can work reliably it would be cost effective to keep them. I’d have to learn about carbs from scratch though. For EFI I was planning to source an EFI bike’s ITB system and mate it up to a local engine management system, using a 60-2 trigger wheel. After adding a fuel pump etc I suppose it is a more expensive route, but can be very reliable with virtually no maintenance once done.


Looking at the motor last night (it’s opened right now), I saw one of the pistons has a damaged ring land. What do you guys think of this 69mm kit? The price seems really inviting compared to Wiseco. Can the stock cylinder sleeves (I think you call them barrels on a bike?) be bored out that much? Should I just go with stock replacement pistons rather?

Aren't the shock mounts on the 440 swing arm farther apart than the 400? Meaning they wouldn't line up with the ones on the frame? Was thinking I'd add spacers or something.

Gonna drop the rear soon and play around with the wheels and parts, see what's what. Thanks for the replies.

That's Rex.
On Dr. Jekyll I swapped out the stock 400 swing arm for a 440 LTD unit.
It added about 2 inches to the wheel base. Both sides of the 440 arm are symmetrical,
unlike the 400. The added length is unnoticeable with the stock rear fender unless you
know how short the KZ400 wheel base actually is. On Mr. Hyde I used a modified
KZ550 swing arm. A benefit of using the later swing arms is needle bearings are used
instead of bushings. No need to move the shock mounts. Everything bolted up except
for the axle spacers since I kept the KZ400 spoke wheels.


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