KZ750 ignition issue

So, I have been working on my bike, almost a complete rebuild. piston rings, with all new gaskets up through the head, no valve work, but all valves checked out. Now onto the electrical part- I have a new Dyna S wired up to new Dyna 3.0 ohm coils. Cylinders 1&4 do not set off my timing light, but do have strong blue spark. I've replaced spark plug wires twice, after I checked the coils, and they read at about 8.7 volts each with ignition on, and battery somewhat drained (battery was at 11.5V). Now, whatever power I check is at ~8.5V (power lead in, grounded to the frame). The tester light I used to check the static timing lights up from the Dyna S. 1&4 still will not spark. All have sufficient fuel.

Do this, and re-check the ignition coils input voltage:

Cleaning Motorcycle Electrics

Get some of the De-Oxit DN5 electrical contact cleaner and figure on spending a good day going from the front of the bike to the back. It’s a plastic safe cleaner/preservative. www.deoxit.com is their website, and can be purchased at most electronic supply stores.

On the older Kawasaki's, a majority of electrical connectors are inside the headlight housing requiring removal of the headlight, then the fun begins.

Do one set of electrical connectors at a time to avoid mixing up what connects to where. Usually disconnecting, spraying with De-Oxit DN5 and reconnecting is about all you'll need.

However, when encountering the green crud of corrosion, a brass wire brush may be needed on the pins you can reach. Some 400-600 grit wet and dry sandpaper strips rolled into a tube should reach the male and female pins in the more difficult to clean connectors.

Smoker’s pipe cleaners, cotton swabs and wooden toothpicks work as cleaning aids.

Really small electrical connectors may require the use of a welders tip cleaning tool assortment.

Most pins in the connectors are coated with a thin plating of tin, and others may be nothing more than copper or brass.

If moisture is added, the resulting corrosion lowers the voltage/current being carried causing dim lights, slow engine cranking, slow turn signal response and lower input voltage to the ignition coils resulting in weak spark.


The left and right handlebar switch pods will need attention too as they have circuit functions like turn, horn, run/stop, and start.

Usually a spritz or two with actuation of the switch is about all needed for these switches unless corrosion is detected and then careful disassembly is required.

The ignition switch may or may be not sealed to allow spraying the internal contacts. I urge caution if attempting to open this up as springs, and ball bearings may fly out never to be seen again!

If your bike has the older style glass tubed fuses, I suggest replacing them as vibration can cause internal failure. AGX is the type used, and most auto parts stores can get them for you.

Clean the fuse holder clips, looking for signs of overheating(discolored insulation, signs of melting). I use metal polish on a cotton swab, followed by spraying another clean swab with the De-Oxit DN5 and then rubbing the inside of the fuse clip.

All battery cables must be clean and tight for maximum current transfer. Check the cables going from the Negative(-) battery terminal/post to the engine mounting bolt

Also the one going from the Positive(+) terminal to the starter solenoid and from there to the starter motor.

If any battery cable feels ”Crunchy” when flexed, replace it as possible corrosion is inside the insulation.

Each "Bullet Connector" will have to be sprayed to ensure good connectivity, especially the ones going to the energizing coil of the starter solenoid.

The alternator output “Bullet Connectors” are usually behind the engine sprocket cover and will need inspecting and cleaning too.

The turn signal light sockets will benefit from a spritz from the contact cleaner along with the tail light/brake light socket.

Some brake light switches can be sprayed on the actuating rod, with the spray running down inside to the electrical contacts, others may be sealed requiring replacement if the switch is intermittent in operation.

Some people put the Di-Electric Grease on cleaned terminations/connectors, I don’t, as I’ve read/heard it can cause problems when it gets hot, actually insulating the connections, so the choice is yours to use or not.

I think I've covered about all of the electrical systems on the bike.........

Re: Cleaning the many and various Motorcycle electrics

I used the De-oxit D-5 spray on all the electrical connections of my 78 Kz1000 that had sat for twenty years .

When I parked the bike in 92 I was starting to have troubles with some of the electrical system, but after pulling everything apart and giving it a spray , reconnecting the connectors and working them back and forth a few times, then gave them another shot of spray to wash them off before the final reconnection.

Everything still works perfectly and has for over 7000 miles this year.

I am extremely happy with the results , a lot of the connectors were green when I started and after the cleaning they looked new ( shiny gold )

I found the Deoxit D-series, D-5 spray in a 4 oz can at a big electronics store called Frys in Illinois, don't get the small cans at Radio Shack , they are different and meant for computer type stuff.

store.caig.com/s.nl/sc.2/category.188/.f

Trust MFolks , the guy's a true rocket scientist and really knows what he's talking about.
JD

I just did a random spot check with the headlight off, and I noticed a huge voltage drops from a bunch of different points, so it looks like this is really where I need to begin. Thank you very much!

It really doesn't take much corrosion, to lower voltages on these older bikes, so take your time, and be through. If you suspect the soldered joints are failing in the left and right handlebar switch pods, I've got a repair procedure for those too, just ask...

Found some deoxit at guitar center. Went through the entire bike, including light switches and starter switch. I got the voltage at the coils to 11.2, the battery is at 11.7. The ignition light is still not working on cylinders 1 & 4. I also swapped coils again, to no avail. Cylinders 2&3 light up like Christmas trees. I am completely at a loss. So far, I know its not the coils, not the voltage, not the battery, not the starter switch.

I cleaned the pickup coils, but there's not much to clean on the Dyna S, as the housing is all plastic. This seems to be the only variable left in the system, although I know a complete circuit is made when I static time, so I know that at least the wires in the Dyna S are intact.

Hopefully someone reads this- I have spark when plugs are out of the block on all cylinders (still) but I changed out the Dyna S ignition, and now don't get steady spark on any cylinders, BUT, I get intermittent spark on all cylinders now. This sounds like a grounding issue... I checked out my battery ground and it was grounded to the frame, which seems ok, but there was a little rust. I also thought the battery was supposed to be grounded to the engine? Is that correct? I can't really tell from the wiring diagrams, so if someone could steer me in the right direction, I'd be happy! Thanks!

Every Kawasaki I've owned had the Negative(-) battery terminal connected to an engine mounting bolt with a cable. I believe it's about 8 awg(American Wire Gauge) in size. Make sure there is no paint, or corrosion where the Negative connection will be.

MFolks wrote: Every Kawasaki I've owned had the Negative(-) battery terminal connected to an engine mounting bolt with a cable. ....

+1

They came from the factory with the ground wire connected to the engine, not the frame. Ed

I rerouted the ground to an open location just in front of the top rear engine mount, and the wire for perfectly... Go figure... I still don't have any idea as to why I'm getting sporadic spark though... Any thoughts on that? I'm going to pick up yet another new battery tomorrow and see If the ground reroute and new battery help any. I think my current battery may have overcharged, and could be faulty, but still shouldn't be a reason why the bike isn't sparking inside the cylinders... I'm hoping it has to do with the grounding issue, any thoughts before I get the battery and test the ground tomorrow?

How's the fuses look? Are the primary(small wires) secured good to the ignition coils? Kawasaki used 1/4" push on electrical connectors for the ignition coils, but the after market coils has terminals that could short out on the metal mounting spacers for the coils.

Check the sparkplug caps,especially if they are original, as heat, vibration and age can cause them to fail, or become intermittent. When replacing the sparkplug caps, cut about 1/8-1/4" off the end for a better connection. The caps contain a 5000 ohm resistor to reduce the RFI when the plugs fire.

Thanks for the quick response! I've gone through all wiring, fuses, connections. I replaced the spark plugs with the stock NGK be8es or whatever the manual called for. I have Dyna suppression core wires with the rubber boots on, as the wires needed to be made. They have the connections supplied by Dyna. The wires are connected into brand new dyna 3 ohm coils. Do I need suppression caps on my wires?

emptypond wrote: ... Do I need suppression caps on my wires?

Nope.

Good Fortune!