TOPIC:

Hello all,

I had one of these fall in my lap.

Stock 77 KZ650 B model.

I rode it home 130 miles or so. it need attention.

Starts and idles fine. Cylinders seem to drop out at over 5500 RPM. Pulls strong to there in each gear. I also noticed oils weeps from cam covers & plugs and head. Not much but enough to leave a mist. Standar ignition, air box and exhaust (broken left baffle.

I figure, valve clearance check, retorque of all bolts, and oil filter swap is in order. Any ideas on the power above 5500 rpm?

Any help appreciated.

R

Possibly a stuck ignition advancer or fuel starvation due to a clogged petcock, fuel line, or carbs. If it has points ignition, could be worn or improperly adjusted points.

Yes, look at you ATU auto timing unit under the right hand points cover.

It is a simple centrifugal advancer that controls ignition timing advance. If you have a strobe see where yuor timing is at idle, and it should advance as rpm increases. Full advance is at about 4000 rpm IIRC.

If that is the problem clean and lube it.

Another place to look is your coil connections, if you have an oil leak the terminals could need attention. Clean the male terminals up on the coil and I usually replace the female connectors. Replacing your HT leads and plug caps is always worth doing on old bikes - use 7mm wire.

If it is original, and I think it is, your bike has the best red paint I have ever seen on a KZ650-B1. The red KZ650 paint almost immediately fades to a burnt orange color and over time changes to a silvery orange. I saw this on bikes that were only 1 year old. So if that is the original paint it has been kept covered most of its life. If it is a re-paint, the painter took the time to get the striping correct. Very nice. I sincerely hope you do not plan on changing the paint - what you have there is exceedingly rare.

The mufflers are from a different model.

I suspect the 5500 rpm problem is either the points or possibly dirty carbs.

STEP 1 would be to replace the points and condenser with new Kawasaki parts. If you need a tutorial on how to do it just ask as I already have one written up for the 1977 KZ650, and I'll be happy to post it. Replacing the points will give you a good baseline and allow you to clean and lube the advancer. As stated, a sticky advancer will cause problems. The valve clearances on these bikes don't change much at all, so it's worth checking, but highly unlikely to be causing any problems - especially not the 5500 rpm thing.

In the off-chance the problem is dirty carbs they are not terribly dirty or it wouldn't run as well as it does. I cleaned mine without separating them from the holder (I had let them sit with fuel in them for a long time). They cleaned up easily that way and when done they ran like new. Other than gaskets for the carb bowls DO NOT replace any carb parts. The parts in the carbs do not wear out, and aftermarket parts are not as precise as the originals.

To put things in perspective; I have owned my KZ650-C1 since it was new (38 years) and have always done my own maintenance. I have put more than 57,000 miles on it. There's at least one member here that has put 3 times that many miles on his!

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

Here's a pic you may find interesting:
jarlef.no/Kawasaki/Images/Z650/p2/Z650B1adJP.jpg

Thanks appreciate the info. The bike came with owners and service manuals. I pulled the cam cover and will check valve. Quite a bit of oil in the can area. Looks like someone used rtv there. The gasket is quite lacquered and stiff. I have a law cdi coming. The advancer looks fine. Felt and spindles was gunky. Some oil at the head in the can recess areas by head bolts. Most of the oil film was from can cover plugs. Wiring looks remarkably good. Gravity petcock. All stock from there. Will put in cdi. Probably best to get another. I see the manual does not indicate rtv. Any onward. BTW. Rolls and handles great compared to my FI 1500;Vulcan it feels like a moped. R

You should not use any sealant on the cylinder head cover. If you replace the half-moon rubber cam end plugs you should put sealant on the bottom half (the curved part) of them. Ed

Yep, no RTV on cam cover gasket per manual. WIll be digging in more valve clearance check tonight. More to come.
Any tip on best way to remove old gasket ?
R

Ok valve clearance checked. All good and within spec. See pic.

Problem - how can I get the gasket material off of the head. It is old and severely lacquered to the head. It came off the cover clean. I didn't want to take a razor blade to it as it is on there too tough to do so without possible harm. I'd also like to not have to pull the cams just to clean out the dam lifter valley from the scraps of gasket falling in there. I used a paint brush and carefully painted the gasket with ATF. Maybe that will loosen it up. On my vulcan

I have also soaked the gaskets in ATF before install. They never stick when this done and don;t leak.
Tell me someone knows of a secret chemical. Peace out, any help appreciated.

Getting closer but this blows.

R

Maybe try a plastic putty knife. Be sure to stuff a rag in the cam chain tunnel while scraping off the gasket so none falls into the abyss. I don't know why folks feel compelled to glue gaskets on when it is totally unnecessary and only leads to the mess you now are dealing with. Put the new gasket on dry. I've done it that way on my KZ650 for 38 years. I've never had one leak, and I can re-use the same gasket for decades. Ed

If it came off the cover without breaking, no need to replace. Of course if you have oil leaks and are replacing the cam end plugs, getting them out without breaking the gasket will not be possible. No way to remove the gasket easily. Takes patience and a decent scraper. I hate scraping gaskets so try my best to not break them so they can be reused. Not always possible though.

Well, the gasket is 99% off the head. I am not sure, but it looks to me like cement was used on the head. Several applications of thinner by brush loosened it except near bolt holes. That was still finicky. I used an exacto knife and tread lightly although it was impossible to do so 100% scratch free. Used a 1000 grit wet sand paper very lightly on the entire mating surface. Shop vacuumed the oild and gasket bits from the cam valleys. very clean now. I think it looks fine. In the past I have soaked gaskets in ATF to condition them. The manual says no sealant here, except at cap plugs. I was thinking a very thin coat on the gasket surface that touches the head leaving the top dry. Some clear sealant on cam plugs and gasket outside where accessible. What say ye?

BTW way great advice on covering the hole to the abyss. I had an exacto balde snap and land on the towel - yikes!, would rather not split cases.

Thanks any help appreciated.

R

DON'T DO IT!!

Unless you really gouged the mating surface putting sealant on there is a bad thing to do. Other than that there is no reason on earth to put sealant, goo, bathroom caulk, chewing gum, or anything else on that gasket or the mating surface. If you do put crap on it you will have to repeat the scraping mess that you just finished doing. Putting stuff on there is crazy. Again. DON'T DO IT!

Oh, did I mention DON'T DO IT?

I have never used any sealant of any type on that surface or gasket in the past 38 years and have never had one molecule of oil leak out. Count how many bolts holds that cover on. There are tons of force squeezing that metal and gasket together. Ed