Newly acquired KZ400

Hey guys,

recently purchased a 74 KZ400 with just over 19k miles in what I would describe to be stock, unrestored condition. The only part I am not 100% sure about is the exhaust, and maybe the paint on the tank.

It runs really well- took it in to a local motorcycle mechanic for an inspection and a once over. Ended up replacing the chain, lubing the clutch and adjusting linkage.

This bike was purchased for my wife (her first) my Harley is too big for her. I will say after riding this KZ around for a bit, I am quite impressed with its performance and operation.

Overall it has a few oil seeps (no surprise for a 40 year old bike) but everything seems to function as it should.

Our plan for this bike is to clean it up a bit, polish the aluminum covers and forks, probably end up ordering some gasket kits to replace some that are seeping. We may end up replace the turn signals with something a little more subtle. She wants to possibly replace the tail light, she likes the look of the chrome fender and wants to show it off more.

No plans to cafe, bob, track or anything- just a fun little street bike for around town and weekend afternoons. Between the KZ and my HD we want to load up some lite gear and do some summer motorcycle camping.

Here are a few shots from this past weekend. We're in the Allentown PA area, always checking out backroads and sights in the Poconos.

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.

PICTURE 1

PICTURE 2

PICTURE 3

PICTURE 4

PICTURE 5

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 oil (and pretty much all other 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. Early AUTOMOBILE oils contained zinc phosphorus compounds (ZDDP) to protect engine components from metal to metal contact. This was good for engines, but it was found to be destructive to catalytic converters. Consequently, in AUTOMOBILE oils ZDDP was virtually eliminated and replaced with different chemistry generically referred to as "Friction Modifiers." These work fine and offer good protection for normal AUTOMOBILE engines. However, today's AUTOMOBILE oil "Friction Modifiers" are destructive to wet clutches. KZ bikes (and many other brands) have wet clutches. As a result of these oil chemistry changes a distinction needed to be made between those oils which are suitable for wet clutches and those which are not. That distinction was documented by the Japanese Engine Oil Standards Implementation Panel (JASO). JASO developed a number of different oil specifications for different applications. The specifications that apply to 4 stroke motorcycles fall under the "4T Specifications." Within the 4T specifications the JASO MA class oils are specifically formulated for 4 stroke motorcycles with wet clutches.

There are synthetic, semi-synthetic, and non-synthetic oils that meet the JASO-MA standard and any of them will work ok. However, using oils that are not designated as meeting the JASO-MA standard is destructive to KZ clutches.

Good luck with your bike. Ed

And your little helper. Get the 3/8" one so you can use it with sockets. For stubborn screws and bolts.
Steve

Ed, it looks like you may become my new best friend. Thanks for taking the time to post all that information.

You are spot on with the info about the service manual, the guy I bought the bike from gave me a Haynes manual which is OK, not great. I ended up finding a Kawasaki FSM online and picked that up. As I mentioned, I am new to 40+ year old Japanese motorcycles, but right at home under the hood of my Jeeps or Harley's.

Your mention of the deceiving phillips screws is much appreciated. As you can imagine, on a bike with 19k, those screws appear to have seen some time with a screwdriver. I have actually found a couple places online to order replacements. I have successfully been able to remove several (as needed) so far, but your suggestion and guidance for the JIS bits is fantastic.

As I said, it is a fun little bike, I'm sure it'll need some TLC, but nothing major for now. From what I've seen so far, there is a wealth of information on this site. Thanks again for preemptively providing me with that info, and thus saving me headaches down the road.

I admit, I wrecked a number of screws before learning (on this site) about the JIS standard. Here's a diagram that compares JIS to Phillips. Ed

The tank paint & mufflers aren't stock. The fuel tank had striping & the oem mufflers had cone ends instead of megaphones. I think the stock color is called Halibut Blue & there would have been multi-colored stripes. the link below is for the 75 model, but I think the 74 color scheme is the same.

1975 KZ400 ad

Looks like someone has already replaced the stock mini-ape handlebars with a pair of superbike-style bars. It's a good looking bike. Congratulations. I hope you and your wife enjoy it.

The lack of stripes on the tank was the giveaway to me also on the non stock paint. And as you pointed out, the exhaust isn't right either.

As far as the handle bars, those have been changed also, but when I bought it the seller gave me the OE bars with the deal. I may end up switching back to them as it may make it a little easier for my wife to ride. So far it has been fun.