'82 Spectre Coil issues

I finally got my carbs cleaned and running good on my '82 Spectre 750. I ran into a new problem over the last few days. Now, when I'm running along, the tachometer will drop from "X" reading down to zero rpm. I'm cruising at 40 mph no problems, then the tach drops down to zero rpm and I have no power and I'm bogging down. The motor itself is still running when tach reads 0, just low on power, feels rough, and won't accelerate so I suspect it's running on two cylinders when the tach drops off. Eventually after nursing it along (20-30 seconds) the tach starts giving a reading again. As soon as the tach starts working, all my power comes back. (Back to running on 4 cylinders?) I think my coils are working intermittently. Has anybody experienced these symptoms? I'm planning on replacing the coils with parts from Z1. I just want to isolate the problem first. Thanks!

Sometimes it runs great through low and mid rpm before it drops to zero, or I've had it revving at 9,000 before it drops to zero. It definitely seems to happen at any rpm range, which leads me to believe coil problem. Any thoughts or advice are greatly appreciated. It still has stock coils from '82. I'm sure they could stand an upgrade.

Just an idea -- I did this to my 82 Spectre -- replace the plug wires before changing coils. My experience with coils is that they either work or they don't. Intermittent problems would suggest to me corroded or failed connections.

Maybe try this first -- unscrew the plug wires from both ends (coil and plastic spark plug boot); trim off about a quarter or half inch from each end with a good wire cutter to give you a new connecting center core (my original Spectre wires were twisted copper strands in the center and it was discolored for about a good half-inch on each end), making sure the brass screw on the inside of the coil & plug boot are clean and look good; and retry it.

Also clean all the connections for the two coils.

Won't cost anything except a half hour or so of your time, and it might fix the problem. If not, all you wasted was a little time.

You can get new plug wire by the foot at the auto parts store, mower or bike shop. It was under a buck a foot at O'Reilly's last year, I don't know their current price. Don't forget to measure both the coils primary and secondary resistance. Also the Plug Cap.
An upgrade to a new set of coils/ wires, may be better for reliability.

I've installed new plugs and wires before this problem started. Now I'm thinking I need to look elsewhere. Probably just more dirty connections. Kind of perplexing that it's running like a beast until tach stops, then it has virtually no power. It will be running perfect after I figure out what the deal is.

Thanks for the replies.

Would assure:
Full battery voltage being received at coils;
Integrity of negative battery cable ground connection;
Red or red/yellow wire attached to coil primary isn't internally frayed.

Good Fortune!

Factory tach or aftermarket? If factory, the tach gets it's signal from one of the ignition coils, so do some tracing back, it might be a dirty connection, or a broken wire making and breaking contact.

I'd chase the tach lead, especially around anything that may have rubbed through the insulation. If it shorts to ground, I believe it'll effectively drop that coil.

Disclaimer: This is under the assumption that the tach is driven directly by one coil and not the other. I haven't looked over a schematic for this bike.

It's got factory coils.

Been busy with work and I barely have time to work on my machine. I've got today off so I'm going to check everything out.

When I fired it up this morning, the tach was sitting on zero and only half the motor was running. I fiddled with the connections on the coils and after that it started fully running again. I don't think the coils themselves are bad, it's probably the wiring somewhere (as always on this project)

According to the wiring diagram the tach receives its signal from the right side coil as you're sitting on the bike, the coil that controls Cyl #1 and 4 on the 750. Those are the cold cylinders when the tach isn't working. I'm going to check the black wire that goes to the tach first. It's all wrapped up with the other wires. I guess it's time to pull all the tape off.

I was also thinking about redoing the connections where the wires clip onto the coil. They snap on tight, but they feel loose when you wiggle them around. Maybe it's just doesn't have good contact. Anyway, headed down to the garage. I'll let you know if I find anything out.

Thanks for the input.

Would assure good continuity via the black wire between the left-hand pickup module and igniter, and between the igniter and ignition coil.

As known, the pickup module works with the igniter to repeatedly ground and unground the coil's primary winding.

While grounded, the coil is charging.

When the pointed rotor passes the pickup module, the coil's ground via the black wire is momentarily interrupted (coil becomes ungrounded), which is the event that causes the coil to fire.

Good Fortune!

I'd do this too:

Cleaning Motorcycle Electrics

1. Get some of the De-Oxit 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. It can be purchased at most Radio Shack Stores or any electronic supply places. Or use any plastic safe electrical contact cleaner(NOT WD-40 !).

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

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

4. 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.

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

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

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

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

9. The left and right handlebar switch pods will need attention too as they have circuit functions like turn, horn, run/stop, and start. The older Kawasaki’s have reports of the soldered connections crumbling, if your bike has this problem, just ask, as I’ve got a repair procedure for this.

10. 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.

11. 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!

12. 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, along with boating supply stores.

13. 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 and then rubbing the inside of the fuse clip.

14. 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

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

16. If any battery cable feels ”Crunchy” when flexed, replace it as possible corrosion is inside the insulation. Inspect all heavy duty battery cables and the smaller wire terminations(Bullet Connectors), for failed crimps, and those used in the electrical connectors, as they can fail over time.

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

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

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

21. 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.

22. 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.........

“I spent a weekend going through every electrical connection and switch on the bike with a little scotchbrite pad and DeOxit - what a difference! Everything was brighter, gauge backlights, indicator lights, turn signals, I was getting a nicer spark, it fired up quicker, etc. Well worth my time. WELL worth it! “

From a forum member at www.kzrider.com





Why WD-40 Should Not Be Used On Motorcycle Electrical Items.

For many years, I was proponent of the use of WD-40 on fuse clips, fuses, switches and connectors. After hearing of other peoples experience with intermittent and sporadic activity, I shrugged it off as maybe they did something wrong in the application of the product.


It wasn’t until the time I rode my 1982 GPz1100 B2 model to downtown San Diego that I encountered the problems others had gone through.

After concluding my business downtown, I walked to where my bike was parked, turned the key to unlock the forks, and prepared to start the engine. The key was in the "On" position, yet I had no lights in the dash panel, the fuel pump was not running(I have FI), and the horn and tail light were not working.


Puzzled as to why nothing electrical was happening, I remember my earlier conversations about how WD-40 will over time become a non-conductor(more like an insulator). I had some pieces of 400 and 600 grit sandpaper in my tool kit and with them was able to scratch away the coating from the WD-40 on the fuses and clips.

After removing the insulating film, the bike started and ran like it should. Since that time, I’ve told people about the problem with WD-40. If you must use a contact cleaner, I recommend getting some "De-oxit" from Radio Shack Stores or any good electronic supply store.

I believe I've got it fixed up now. All I did was cut off the old female connectors and crimped on some new ones. The old ones were so loose I think they were vibrating around loosing contact. The new ones were hard to push on and very tight. So far the tach has been rock solid instead of intermittently jumping around, and it's running great. Also, wired in the new "blade" fuse block today. Hopefully my electrical issues are a thing of the past.

Going to the DMV Monday to get all the paperwork finished. I'll see you guys on the street!!

Thanks for the input on this thread and others to help me get my KZ back on the road.

A nice, simple repair, rather than tearing into the harness, looking for failed splices.