1976 Kz900-A4 Fix-er-up

So I thought I'd start getting some info out here regarding my bike. I've been working on it for a couple years now (as my sig says, mostly making things worse) and recently took the engine in to Motorcycle Performance here in Madison to have the engine rebuilt. Numerous issues found with the existing engine. (Bill who is doing the engine work was "not happy" with the way state things were in). Apparently the cam chain hadn't been adjusted for quite some time and the front idler component was "missing". I'm expecting them to find it in the bottom of the crankcase. I also found that at some point the rear idler was installed backwards and the cam chain was running again metal instead of the rubber wheel. What a mess.

Anyways - here's the deal. I'm getting the head rebuilt, Kz1000 jugs installed, bored to 1076cc. Probably sticking with the stock airbox, existing exhaust, and the VM26ss carbs for now, but in the future I'd love to get a Kerker and some larger carbs to take advantage of the larger displacement/more efficient exhaust.

The bike is apart right now - down to the frame. I'm planning on repainting the frame and replacing as many wear parts as possible before reassembling (i.e. bearings, bushing, seals, etc).

I have a blog started where the project will be updated - mostly for my own benefit/documentation. It can be viewed here:

www.waterspoutsoftware.com/wordpress

Thanks for everyone's help here!

I'll post here what I've obtained from "Wired George" about improving the ignition coil input voltage on these older Z's and KZ's. As the article states, many people confuse carb problems with weak spark.




Re-powering Ignition Coils To Get Full Power
By Wired George (his website is www.wgcarbs.com )
Condition/Symptoms:

A problem common to MOST vintage motorcycles is often characterized by hard starting, rough running, backfiring, and sooty or fouled spark plugs.

What most people recommend?
Since the plugs are sooty or fouled, the air/fuel mixture is often singled out as the culprit, in other words, your carburetors' air/fuel mixture is too rich. You will be told to use smaller main jets, move the clips on your jet needles up or fiddle with your mixture screw or pilot screws. These recommendations MAY lessen the plug fouling and other symptoms but may also have no effect, other than cause tuning problems which ultimately only make matters worse.

OK, have you tried these things to fix the "rich" problem?:
· cleaned air filter or pods
· rebuilt carburetors and know that their innards are clean and properly jetted
· know there is no crud in the bowls or being passed from the tank
· carburetors have correct float levels

If you have checked these things and the problem with sooty or fouled plugs is still there, then your problem may NOT be carburetor induced! Consider that three things are necessary for complete combustion.

correct air/fuel mixture
good compression

good spark
If you are confident your air filter(s) are clean, the carburetors are jetted appropriately, then ensure you have good compression by adjusting your valve clearances. Read the Valve Clearances article in our wg's Tech Stuff Index area. Last, if your ignition components to include, points/condensors, OEM ignitor/pickup coils, plugs, plug wires/caps or coils are old and their condition is suspect, replace them. There are troubleshooting procedures outlined in a Clymer manual or Kawasaki Factory Service Manual which give step-by-step procedures for checking these components functionality.

WHY DO I HAVE A WEAK SPARK WITH GOOD IGNITION COMPONENTS?
The voltage feeding your ignition coils is insufficient to cause the coils to fire a strong spark! This problem is common to almost 100 percent of all vintage motorcycles... Check it out yourself!

Get a multi meter and put the POSITIVE probe on the coil power wire. This wire is attached to a lug on your coil and will be either yellow/red, pink or red (depending on Kawasaki model). Put the NEGATIVE probe on a frame or engine ground. Put the multi meter in VDC scale. Turn the key on with the kill switch in the RUN position. You do not have to start the bike. If you get less than 12 VDC, your coils are being robbed of power. Why? Old wiring, connectors and switches!

The issue is that YOU HAVE A WEAK SPARK due to poor coil voltage and no amount of tuning will rid you of the symptoms or soot/plug fouling. We suggest you power the coils using a separate circuit via a standard automotive relay. Bosch and other electrical component manufacturers produce relays that will work for this application. Relays can be purchased at most auto parts stores and places that install automotive stereos and alarms. You can also purchase relays and pigtails on the web from places like Parts-Express .

These relays have STANDARDIZED number coded connectors. A drawing is supplied at the top of this article which shows how to wire the relay into your bike. After rewiring, your coils will fire a spark as never before. The soot and rough running will be over when you have made this simple modification. The relay can be mounted to the motorcycle frame or battery box.

To perform this modification, buy the following:
12 gauge wire
18-16 gauge wire
soldering iron and light duty rosin core solder
heat shrink wrap (3/16”)
standard automotive relay (four or five pin)
standard relay pigtail
inline fuse holder rated for 30A
pack of 10A (inline type) fuses
press-in male connector (see the dual-outlet coil connector over your valve cover)
crimp on female lug connectors for 18A wire and 12A wire
cable ties
Need help finding a relay and pigtail? The relay is at the top of the page and a corresponding pigtail is linked towards the bottom... See this link:

www.partsexpress.com/pe/showdetl.cf...tnumber=330-070
Installation Steps:

NOTE: first disconnect your battery!

The relay can be attached to a nut/bolt on your battery box under your seat. The relay has male connectors. While it is possible to use crimp on female connectors attached to the relay male connectors, this type installation WILL oxidize quickly and fail. We suggest using a standard relay pigtail which plugs onto the relay and has 5 wires coming off it that correspond to the connectors on the relay. Connect the relay to the motorcycle and then solder wires to the pigtail. Once all connections to the pigtail are complete, plug the pigtail onto the relay.

Relay Ground Connection #85
Solder / shrink wrap one end of a 18 -16 gauge wire to connect to relay lug # 85 wire on the relay pigtail. Use a piece of wire sufficiently long so that it can be connected to the motorcycle’s main engine ground point. Find this location by tracing the negative battery terminal wire to where it is secured either on the frame or engine. To properly solder a wire to wire connection, join the wires by twisting them together. Warm the joined wire ends with a soldering iron and hold solder on top of these wires until this solder melts and permeates the joined ends; that is, it penetrates through the wires. Once the connection is soldered and cools, pull a piece of shrink wrap over it and melt the shrink wrap with a lighter or heat gun. Install a crimp on “eye” type connector (it should be blue) on the end to be connected to the ground. Remove the bolt securing the main engine ground wire and install the relay wire connector and main ground wire and retighten the bolt. This is the relay GROUND!

Power to Relay #30
Solder / heat shrink one end of a 12 gauge wire to connect to relay #30 pigtail wire. Put about 1 inch of heat shrink onto the free end of the wire and move it towards the relay and out of the way for now. Cut the wire on the inline fuse to make two ends. Put a 10A fuse in the holder and reconnect. Solder the inline fuse end to the 12 gauge wire connected to the relay pigtail. Strip a bit of insulation from the other end of the fuse holder wire and install an “eye” type connector (should be yellow). Loosen the nut that retains the positive battery connection on the starter solenoid and place eye connector end of the wire onto the stud where the nut was removed from and replace the nut and retighten. This is the relay POSITIVE 12 VDC battery connection.

Relay Trigger #86
Find the yellow/red wire that had previously been used to power the coils. It comes out of the wiring harness above the valve cover. This wire terminates in a dual outlet female connector. From this connector, voltage connections are made to both ignition coils. Remove these connections and discard them. Solder / shrink wrap a wire coming from the #86 relay pigtail sufficiently long to reach this connector. Install the press-in male connector and plug the connector into the dual outlet connector coming off the wiring harness above the valve cover. This is the relay TRIGGER. Note that the trigger wire is controlled by the motorcycle kill switch which must be in the ON position for the relay to function.

Power Wires to Coils #87
The last piece to be fabricated is the positive wiring to the coils. From the relay pigtail #87, solder / shrink wrap a length of 18 ga. wire sufficiently long to reach the rear of the coils. At this point, solder / shrink wrap two wires that will each go to the front of one of the coils forming a “Y”. Install a blue crimp-on “eye” type connector onto each leg of the “Y” and install these connectors onto one of the two small lugs on each of the coils. Note that the OTHER wire on each coil will be either black or green. Leave these wires alone. These are the ignition wires. The coil’s voltage HOT WIRE is now complete.

Dyna S User Note!

If you are using a Dyna S ignition, there will be a “positive” wire coming up from the ignition (located under the points cover) that needs to be connected to a power source. It is a red wire. This wire can be spliced into the HOT WIRE “Y” from the #87 connector fabricated in the last step. Solder it into the “Y” and shrink wrap. There are ignition wires coming from your electronic ignition pickup coils or Dyna S ignition (or points) . These will not be modified.

You are done at this point but wire ties "pretty up" the installation and ensure no wires drop down and lie atop the valve cover or engine. After the addition of the relay, when you start the engine, with the kill switch in the “ON” position, your coils will be powered by the new circuit you added and your spark will be much, much stronger. Say goodbye to constantly cleaning your spark plugs and tinkering with your jetting! The pigtail is beneath and the relay plugs into the pigtail which has wires coming off, making it suitable for soldering connecting wires.

Thanks - I had already planned on doing this as I rebuild the bike. There are a number of posts regarding this mod on this forum.

that seems to be a pretty complete bike youve got to start with,that will make it much easier /cheaper as you go along.

Thanks, Plummen. I got lucky on the purchase of this bike - I was just too dumb at the time to realize it and take care of it. Most of the expense I have will be from things that are my own fault or from not researching. For example - I lost the rear cover to the tachometer, I snapped a bolt on the side cover of the engine, I let the master cylinder go dry and need to rebuild it, I didn't tighten the backing plate on the front disc pad and it flew off while riding. So basically, don't let me work on your motorcycle

But I have learned more than I ever could have imagined, even at this point, and I cannot wait to ride the bike this summer!

I put 9.3 miles on today! It felt so good to be out riding again - first time on my own bike in about 8 years.

Still need to do bodywork, but it runs, idles, accelerates, turns, and stops. What else could you ask for?

Thanks to everyone who's helped out so far! I couldn't have done as much as I did myself without this great community!

Nice to hear that you are riding. Roy

Finally got some pics today, but they were with my cell phone...so they don't do it justice (but they hide the runs in the clear coat that I need to fix/respray).

Pic 2 - the paint is Duplicolor Wheel Paint (yes, rattle can with a two part clear from Eastwood.com - thanks OMR!) but the metallic flake doesn't come through on this low-res camera. I'll have to take them again with a real camera.

Thanks again to everyone here! Especially Plummen, OMR, Patton, Arai, Loco, and the other gurus who helped me with my questions as I went through the project!

The whole thing can be seen at www.waterspoutsoftware.com/wordpress although the pictures are a bit slow to load.

Nice job on a great bike! Definately the best Kawasaki ever made! You did not say how it ran. What two part clear did you use?...Russ

Thanks Russ. It runs pretty good. It has been a good long time since I was on it last, so I'm not sure how it compares in performance to before, but it sure feels fun. I have the jetting pretty rich right now and I think I'm going to leave it that way through break-in. Probably going to go back to the stock main jet (115 on the VM26SS) once I feel comfortable with it.

The clear coat I used is this one: www.eastwood.com/paints/clear-coats/ew-u...clear-2-1-quart.html

The only complaints I have are:
1.) I apparently didn't know how to properly clean my spray gun and ended up with runs while compensating for uneven spray (I have since resolved this issue, but I need to sand it down and paint again).
2.) You can't get a smaller bottle of activator for the quart size clear coat can. You have to buy enough for a gallon.

I'm really happy with the clear, though. It has held up well so far and was really easy to put on.