Please help troubleshooting electrical problem

Howdy, Y'all from Austin Texas.

I've got a 1980 KZ750 H. it's got 30K miles on the clock and I've had it for a couple months. The previous owners, cumulatively did a few funny things to it which I've been on the road to straightening out. Everything was going fine, until yesterday when an Electrical problem occurred that I don't understand - although electrics is not my strong point anyhow. Hopefully the crew of experts here can shed some light on the problem, or at least give me some advice about how to go about testing the relevant systems.

so here's the story:

Since I purchased the bike, I've done the valve clearances, re-installed the factory airbox ,changed to superbike bars and a new 530 chain/sprockets combo as well as a new AGM battery. The bike was a hard starter but saw a minor improvement with factory airbox. in the brief period i've had the bike, i've seen no electrical gremlins - other than a dancing voltmeter needle above 5500RPM.

While I was installing the airbox, I noticed that one of the coils was cracked, and an ignition lead had a small cut. I ordered new 3.0 ohm green dyna coils and new ignition leads which I installed a couple days ago. I'm 99% sure that i installed the coils and leads correctly the bike started first pop and seemed to run a little better overall. THEN:

out on the road - doing about 25MPH around the lake here in Austin - the volt meter dropped to the far left, and the bike suddenly ran rough. stupidly I pulled over and the bike stopped. I got some tools and a multimeter and spark tester and returned to the bike and here is the situation as far as i understand it:

The bike is getting fuel and the motor turns freely.
The neutral and oil light both come on.
The headlamp and turn signals are dead but on inspection, no bulbs are blown
The volt meter is dead regardless of key position
The starter button is inoperative.
I tested the battery at the terminal and it's getting 12.7V
I checked all the fuses - they are intact.
I bridged the terminals of the starter solenoid and the starter turns at normal speed.
While cranking the motor with a spark tester attached, I observed a spark light although it seemed somewhat weakened.
On a cursory inspection, there appears to be no burnt out wires, connectors or switches.

Does anyone out there in KZ land have any advice? Anyone else had a similar situation? Any thoughts about what to test next in order to trouble shoot this problem?

Help is greatly appreciated!

Thanks

I'm 99% sure that i installed the coils and leads correctly

Make it 100% to begin with.

So I went and double checked my installation of the coils.

The mounting bolts are all tight.
The power leads are tight and crimped properly
The Leads from the pick-up coils are tight and crimped properly.
I followed the instructions from dyna - apparently polarity doesn't matter on a system with two coils.
There aren't any shorts that I can see
A multimeter on the red power terminals of each coil, grounded to the frame reads just over 12V

The HT leads are tight, crimped properly and on the correct spark plugs.

This may be a stupid question, but what else could I have done wrong installing the coils?
Again, Electrics aren't my strong point. Is there a procedure to test the installation of the coils?

Thanks

Ignition Coil Primary And Secondary Wiring

Ignition coils on the 80’s Kz1000,Kz1100’s and Gpz1100’s are wired the same, that is as you sit on the bike, the LEFT ignition coil primary(small wires) are two wires, RED and BLACK. The secondary (or sparkplug wires) go to #1 and #4 sparkplugs(your primary wiring may be different).

Read carefully, as the 550’s, 650’s, 700’s & 750’s are wired backwards to what is listed for the bigger 4’s.

The cylinders are numbered left to right as you sit on the seat; #1,#2,#3, and #4.

For the RIGHT ignition coil, the primary wires, again are two wires, RED and GREEN, with the secondary going to #2 and #3.

The RED wire gets it’s voltage from the run/stop switch on the right handlebar switch pod. Your primary wiring may have a different color.

The BLACK and GREEN wires connect to the IC Igniter(if the bike has the Kawasaki supplied electronic ignition) it actually gives the coils their grounds to fire the sparkplugs. The RED wire is common to both ignition coils.

Primary(small wires) side of the coils will read between 1.8 to 3.0 ohms.

Secondary(sparkplug wire ports)side of the coil will read between 10.4K to 15.6K ohms. These ports are wired together, so it makes no difference which is used, as long as the correct coil to sparkplug configuration is followed.

The sparkplug caps should read 5K OHMS(5000), any higher, or a reading of infinity means new caps should be ordered. When re-installing the old or new sparkplug caps, cut about ¼” off the sparkplug wires for a new un-corroded connection.

Never run supression sparkplug wires with sparkplug caps containing the 5000 ohm resistor, as now there will be two (2) resistances in the ignition coil’s secondary circuit, causing weak and intermittent spark.


To stress the ignition coils, take a hair dryer, heat the coils and see if the ohm readings change from cold to hot . If they do, it’s time to buy new coils.

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Keep in mind, the wiring is reversed for the 550’s, 650‘s,700’s, and 750‘s, that is the RIGHT coil primary will be two wires, RED and BLACK with the secondary(sparkplugs) going to #1 and #4.

The LEFT coils primary wiring would be again two wires, RED and GREEN, with the secondary(sparkplugs) going to #2 and #3.

An indication of black and sooty sparkplugs may not mean a carb or carbs are in need of cleaning, but may mean the input voltage is low.

When checking the input voltage to the ignition coils, first have a fully charged battery, and the using a multimeter, set it up to measure VDC(Volts, Direct Current), range of 20.

Put the RED probe from the multimeter on the same terminal that either a RED wire or ones that’s RED with YELLOW stripe, and the BLACK probe on either a good frame/Earth ground or the battery Negative(-) terminal/post.

Depending on the motorcycles current draw( lighting, and other high amp needs) the reading might be 10 volts or more, but if the reading is down around 8 volts or less, this indicates a corrosion or wiring problem needs correcting to improve input voltage to the coils.

These engines have what is known as a “Wasted Spark” that is, a sparkplug will fire during an exhaust stroke. It does no damage and many other motorcycle engines have this design.

I'm pretty sure you wired the coils correctly. If you wired them backwards the engine would cough, spit and backfire but wouldnot have run.
However, I have seen people report that the the mounting posts on the Dyna coils are very close to the connectors and can short easily so perhaps double check or add some insulation to the connections.

The bike is getting fuel and the motor turns freely. Thats good
The neutral and oil light both come on. The neutral, oil light and voltmeter get powerfrom the same wire so perhaps enough power for bulb but not enough to move the needle ?
The headlamp and turn signals are dead but on inspection, no bulbs are blownNot enough power to light the bigger lights ?
The volt meter is dead regardless of key position See above
The starter button is inoperative. Starter button gets power via the kill switch. power also goes from kill switch red wire to harness to coils
I tested the battery at the terminal and it's getting 12.7V Sounds good. Did you check with one multimeter lead on the pos post and one on the frame. Difficult to check if ther battery is charging though without engine running
I checked all the fuses - they are intact. Double check this using multimeter across the fuses. Old style glass fuses can look good but the metal strip can have separated at the end. Remove glass fuses and clean the fuse clips.
While cranking the motor with a spark tester attached, I observed a spark light although it seemed somewhat weakened. It can be difficult to tell. Perhaps not enough power for a good enough spark to start.
On a cursory inspection, there appears to be no burnt out wires, connectors or switches.

Check battery connections and ground. You could jump the starter solenoid so thats a good sign
Check fuses with meter.
Power goes from battery to main fuse to harness to a big connector in the headlight bucket. The big connector connects to the ignition switch which makes several connections - lights, kill switch etc
Hopefully your solution is simple but you may have to trace the above route using a wiring diagram and doing the tests on the ignition switch and right handlebar switches.
I have a colour wiring diagram for the 1980 750E1 which should be similar if not identical to the H1. If you need a copy send me a PM with your email address and I will send it along

Thanks Guys.

I guess I'll be having a busy day Saturday testing motorcycle electrics.
I'll report back with what I discover.

I'd check the factory soldering jobs at the handlebar switch "Pods", as they were not the best, and on the ignition switch too. Vibration may have caused an intermittent connection, especially if during soldering, it wicked up inside the wire, making it brittle, and prone to cracking.

If you need a soldering repair procedure, just ask, as I've got one.

:whistle: Just for the fun of it, I watched this all over again last night.... really nothing new to me but I still really enjoy this stuff:

Check all your grounds
Check all your grounds
Check all your grounds
Check all your grounds
Check all your grounds
Check all your grounds

A dancing tacho on electronic instruments is often a sign of ignition primary circuit problems: the tacho (rpm counter) uses the on/off -ve pulse of one of the coils as a signal. that's why even turning the ignition on or off makes the needle twitch.

The LT (low tension) coil feed wires get baked hot and oily under the tank and is well worth replacing the crimps, on your Dyna coils you need an insulated eye crimp anyway, as opposed to the factory female blade terminals.

You have all your electrics dead, except for your oil and neutral light -and possibly a weak spark. This points to an ignition power supply fault. You may have a big resistance somewhere and the system can only just light up the warning lights, although a continuity meter might not see this unless you check resistance. Look at the fusebox, ignition switch and engine kill switch and handlebar block connectors as the most likely suspects.

A slightly unorthodox method of troubleshooting, but if you don't get anywhere with your meter tests maybe temporarily and carefully 'hot wire' the ignition direct: 12V + battery live and -ve ground pushed into the ignition box 4 way connector. There are two 4 way block connectors, one to the pick ups, the other to to each of the coils and live and ground.
This will confirm whether your fault is an ignition power supply or bad grounding .

Green 3 ohm dyna are more intended for racing, the 5 ohms greys are the road coils. I've used green on mine for years with no problems. As above, use non resistor caps and new leads. Cheapo 7mm copper HT wire works just as good as the expensive taylor leads, Finally, never leave a Dyna S switched on for more than a few mins without the engine running as the coils can burn out.

Tyrell Corp wrote: A dancing tacho on electronic instruments is often a sign of ignition primary circuit problems...............

+1

I once owned a 1974 Opel Manta and whenever the points became pitted and needed to be replaced the tach needle would bounce. It was like having a built-in monitor for the points. :laugh: Ed

FlatJohnny wrote:
out on the road - doing about 25MPH around the lake here in Austin - the volt meter dropped to the far left, and the bike suddenly ran rough.

That sounds like a bad coil...... FYI, if one old coil is bad, best to replace both.