New Member from Mass - Just Bought an '81 KZ650

Hi all, and greetings from the northeast.

I think I got a pretty amazing deal on this bike. I happened to see it on craigslist for $600 right when it was listed so I got there with cash as soon as I could. I think you can see from the photo that it's in pretty nice shape.



The bad news:

• It does have a carb problem because the guy I bought it from replaced them. He said it was running good but the carbs were leaking (probably a stuck float?) so he bought another set and put them on. He was under the impression that the carbs he removed weren't the correct model for the bike, which was why he decided to replace them. Anyway, since he went ahead and tried to fix something that wasn't really broken, it hasn't run right since. It fires right up with starting fluid and sounds good for the 2 seconds that it runs, so I'm not too worried.
• The odometer is broken so the title has a milage discrepancy. It's showing 31k right now so I know the bike been ridden a fair amount.
• The worst part is that it's now winter here so I have some waiting to do before I can really even work on it. My garage is pretty freakin' cold.

The good news:

• He gave me the carbs that he removed so the first thing I did was bring them to a guy I know who can go through them and make them right. My plan is to put those back on and see what happens.
• I absolutely love what he did to the seat, which was recently reupholstered.
• It has new tires, new battery, new coils, and new brakes.
• All of the chrome is in amazingly good shape.

I will definitely have some questions for all you experts here but I think I've probably gone on long enough. I Just can't wait to ride this thing.

-Barry

Welcome aboard! The carbs for your bike should be Mikuni VM24SS type. The photo at the end of this reply shows the difference between the VM24SS and VM22SS carbs. The set shown in your photo appear to be correct for the bike since the bodies are ribbed.

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

PICTURE 1

PICTURE 2

PICTURE 3

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

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 4

PICTURE 5

PICTURE 6

The first thing you should check is the valve adjustments. Too many bikes are sold with carb issues that turn out to be tight valves. Put the battery on a trickle charger to keep it up.
Steve

I have rehabbed dozens of bikes in the last few years after they sat stagnant for some time and stopped running. First thing I do, before even attempting to start them, is pull off the carbs and go through them completely and adjust the valves. Working on a bike with unknowns in these areas is an exercise in futility. The carb O-rings dry out and get hard and brittle with age and if the valves are not adjusted the engine gets damaged.

When you go through the carbs Do NOT purchase junky "carb kits". Get an O-ring kit from cycleorings.com and go from there. You may need gaskets or may be not. If you are not capable of doing the carbs yourself then there are guys around to do them for you. I've got some tips if you get stuck so PM me for more details.

Very nice looking bike Stratman , for 600.00 WOW good find! I am working on my first KZ project myself and this site is great, tons of info shared.

Great post 650ed loads of good info there! I don't know how many know that even the diesel oils are changing now with the new diesel regulations. I am still running it in mine but may switch back to motorcycle specific oil soon. Running the wrong oil will wipe out a cam in very very short order….oil is oil …wrong…... $$$$$$$ Lesson learned the hard way. I ran redline 10-40 after my little incident, motorcycle specific stuff very pricy, but my clutch started to chattered on take off, switched to HD diesel oil and the clutch was much happier but now they are changing it but i am unsure how much,
I have not researched the the oil testes yet on the newer diesel oils but its on my list of things I will never get to :lol:

The carburetors on the bike may need to be vacuum synchronized. As for the original set I would remove the carb bowls & tops to take a look before bringing them to a guy. Compare them to each other to see if anything is obviously wrong. I'd never done carb work before, but doing the complete teardown was easy & I do mean easy. Disassembly was easy & most stuff can only be put back one way, so it's hard to mess up. note: don't mix up the parts. keep each carb's parts separate from the others.

Kawasaki service manual pdf. jarlef z650 . the 1981 KZ650 pdf is in the Files section.

Rear brake shoes. If you don't know the age of the rear brake shoes, replace them. The adhesive that binds the linings to the shoes can fail over time, so a lining can break loose & get jammed between the shoe & drum, locking the rear wheel. It happened to me when rolling the bike off of the center stand, so it does happen. I was lucky.

Thanks so much for the welcome and all the great info.

Steve, I think this really is a carb problem since the bike was registered, inspected, and on the road this past summer (the plate was still on it when I bought it). Things only went south when the last guy swapped them. Will DEFINITELY hook up a trickle charger. Thanks.

Nessism, this one hasn't been sitting around for very long (though I guess it will this winter). For the carburetors, I'm lucky enough to have a retired, mechanical genius friend who can fix most things blindfolded and likes working on carbs. So he'll go through those and I imagine he knows better than to buy one of those kits. I will definitely let you know if things get weird for some reason. Thanks for the offer to help.

Joe, I definitely would have put the wrong oil in it.

Martin, I would have loved to work on the carbs myself, but I have so little time right now and a guy who'll do it as a favor. My plan is to mess with the other set once they come off the bike. I downloaded that service manual (awesome). And you've sufficiently scared me enough to check out those rear brakes. Thanks.

Ed, amazing stuff - all of it was news to me. The info on the carb models is just what I needed in order to figure out what the hell is going on with these things. I bet I have one of each since the bodies look the same. I'll swing by my friend's shop to take a look at the ones he has. As I mentioned above, I surely would have used the wrong oil and most likely would have stripped some screws without your generous help.

You guys have already saved my ass and I haven't even started.

-Barry

I don't think there's anything you can check. If the po doesn't have proof of new brake shoes, replace them. I was very lucky that it happened in the driveway. I just put a piece of cardboard under the rear wheel & slid the bike back into the garage. It would be a real drag for it to happen at speed or far from home. It's a dirty job.
ASBESTOS WARNING. Don't breathe the dust. Don't use compressed air to blow off the dust.

Welcome Barry.

Nice find!
Lucky the previous owner has already put new tires and other items on for you.
They would add up to close to $600.

I believe you did very well at $600 for a 650 in that condition. Patience is the most important thing about getting the engine running well. And like you said, winter is here and it's most likely going to wait until springtime. I suggest filling the gas tank to the top and adding Sta-bil to the tank and turning over the engine to get it into the lines and carbs. That will keep the fuel as fuel throughout the winter. Battery on a tender is a great idea (best if you take the battery inside and hook it up to a tender).

We are practically neighbors, reach out if you have any questions.
Providence, RI

martin_csr wrote: I don't think there's anything you can check. If the po doesn't have proof of new brake shoes, replace them. I was very lucky that it happened in the driveway. I just put a piece of cardboard under the rear wheel & slid the bike back into the garage. It would be a real drag for it to happen at speed or far from home. It's a dirty job.
ASBESTOS WARNING. Don't breathe the dust. Don't use compressed air to blow off the dust.

Well, because the previous owner said it had "new brakes", I figured I could probably tell by looking at the shoes if they were done really recently. I'm guessing they were done with the tires, which still have some sticky stuff on them where the labels were peeled off. But, I suppose if I'm going that far, I might as well replace them. I definitely don't want to experience the scenario you described at any speed.

Thanks again.

-Barry