Plug wires and coils

Hello,

While fighting with my '78 kz650 over an apparent timing issue, I noticed a waxy material under one of the coils (1-4). It looks like there is a small crack underneath.

I also noticed that the plug wires do not seem to be removable from the coil side. I guess my first question is... are these wires part of the coil and not removable? Followed by...could these be the original wires?

Thank you.

The plug wires are not designed to be removed so they are more than likely original.

Z1 Enterprises sells a $36 OEM type coil for Kawis that will work in your bike but it is a four Ohm coil and yours may be a little lower impedance. You might get slightly less spark energy using a four Ohm coil but I doubt you would be able to tell the difference.

I see. I am now thinking that my problem is not timing. I do not have a timing light so I was using the "test lamp method".

After frustration though, I was adjusting timing and dwell all over the place in attempt to get SOME result even if it was a bad-but-different result. Not matter what though, it just runs very lazy. Since I have owned it, I have put 1200 miles on it but I think previously she spent most of her life outside and un-ridden. She is rusty with only 10,000 miles.

Do you know how these bikes behave with faulty wires and/ or coils?

Spark can come and go especially during damp weather,If it were me, I'd get new coils,sparkplug wires and caps.Trouble shooting spark problems can have you think it's a carb problem with time and energy spent changing jets, and cleaning the carbs.

For higher spark energy, get some non resistive sparkplug wires and eliminate the resistive sparkplug caps.I'd check the input voltage to the coils to see if a corrosion problem in the connectors is giving you problems.

Remove the tank,turn on the ignition, run/stop switch to run, and put the RED probe of a multimeter where the RED wire goes. Set the multimeter to VDC(Volts D.C.) range of 20, with the BLACK probe either on a good frame ground or the Negative battery terminal.

You should have battery voltage or very close, if it's down around 8-10 volts, you have a corrosion problem causing weak spark.The right handle bar switch pod has the run/stop switch along with the start switch.

The headlight housing has a majority of the electrical connectors, any which can cause weak votages for the bike's systems.These need to be cleaned. Also the fuse clips can be a major problem due to corrosion/overheated wires.

www.z1enterprises.com sells a non resistive(copper wires)Dyna sparkplug wires with non resistive caps, just cut to length,install on the coils, and you're ready to go.

muddytailgate wrote:

...runs very lazy...spent most of her life....

Would assure advancer is functioning correctly. May need lube, or maybe both clean and lube.

Good Fortune!

Info if needed --

Set gap first.

Then set timing.

Good Fortune!

[Click on image to enlarge view.]

Thanks for the responses. I picked up an analog VOM today to test connections and ordered coils w/ wires and caps and plugs. I will report my findings.

A little more background on the bike. Up until last week this thing was running pretty good. When I bought it I put new points and condensers. Like I said before, I put 1200 miles on it and it went down the road pretty good...85 mph at the top of 4th gear. Now it barely makes it down the road. I has always stared easy (even now) but don't even think about going down the road for a while...like 10 minutes.

Advance seems to operate freely.

im looking at new coils also and wires andcaps.... whats the diff between dyna coils and the 36 dollar ones from z1? besides the price??? i currently have all original 1978 setup.

ace wrote:

im looking at new coils also and wires andcaps.... whats the diff between dyna coils and the 36 dollar ones from z1? besides the price??? i currently have all original 1978 setup.

The dyna coils are typically lower impedance and draw more current. I don't know what coil impedance yours came stock with. You can normally go with a coil which has a slightly higher impedance than stock no problem but going lower impedance can cause overheating, excess current, and coil failure. I think if your kaw has the electronic ignition, the stock coil is about 3.3 Ohms. If you have points, it takes a four Ohm coil like the $36 one at Z1.

85 mph maxed out in 4th?? It should be somewhere north of 110 or so. You probably need new coils and wires but have you looked at the carbs at all?? The reason I ask is because of how slow it warms up. As it gets hotter bad coils should get worse because extrat heat would increase the resistance. Have you ever cleaned the carbs??

muddytailgate wrote:

... barely makes it down the road....

Perhaps combusting on just two cylinders.

Would spray water mist onto exhaust header pipes with engine running to determine which cylinders are combusting.

Good Fortune!

I have sprayed water (actually windex) on the pipes. 2 and 3 vaporizes instantly while 1 and 4 are much colder, which is what make me suspect the 1/4 coil. The 1/4 coil is also the leaky one.

I have not cleaned carbs although I am sure they need it. I am planning a complete teardown this winter but didn't to open that worm can during riding season. Already have an Aermacchi rebuild going. I bought this as a el-cheapo-2up-backroad-rider to get my wife into riding with me. I have created a monster..."is it fixed yet, is it fixed yet"...