Coils

So, I have to ask. How do you ensure that the coils always get full battery voltage?

Voltage measurements inform you of this...

If conductors, terminations, ignition switch and emergency stop switch & regulator are operating ideally (switch current/voltages) whereas no voltage drops are occurring across the switch/terminations themselves you will have the same as your battery voltage +/- a couple hundred milli volts.

See this is where old KZ's have had the issues... Hell, any 30 year old vehicle that in some cases has been sitting in a barn for 20 years will have these issues...

Measure let's say +13Vdc at the battery (+) terminal in idle thus informing you regulator/rectifier/charging system is operating to spec....

Well this same voltage should be the same throughout your system (+) voltage measurements in reference to properly grounded frame, motor battery (-). Measure the voltage at the coil, you have +10Vdc.... :ohmy:

This is where the mod makes a difference no doubt. The mod bypasses the ideal +13Vdc to the coils, works well but.... the rest of the system is down +3Vdc and this is where we're stating technically the problem lies... Don;t bypass it, fix it...

Sure get your beloved KZ home, hell jumper the coils directly to the battery for that but to leave it as is, good enough.... :S Ah well, your KZ do what you want...

Fuses blocks: Old spring glass fuses... Get rid of them... In line rubberized and water proof fuse blocks. If desire is to keep stock then at least replace with new round blade glass fuse holders.

Inspect the conductor into termination points... Stranded conductors frayed, oxidized, dis colored, showing battery acid corrosion (white crap), termination blades dark in color etc... Clean, lubricate, replace connectors as required.

Corroded solder joints on the ignition and emergency switch. Either replace the switches or de-solder and re-solder... Use electrical contact cleaner, spray into the switch itself, this cleaner in most cases will clean and polish the switch contacts.

Harness termination junction block connectors. Clean/polish and in sever cases replace the connector thus new blades...

Ground terminations... Clean ring connector terminals and frame ground with Emory cloth, insure shiny...

In the KZ900 for example... In following the Battery (+) terminal... Feeds into the rectifier then directly into the ignition switch. When turned on, the +vdc is switched into the starter button, emergency stop switch and regulator. From there, directly into the coils....

Not very many places for this Voltage drop to occur. Unless... you have a weak termination somewhere that is partially shorting your electrical system to ground thus dropping voltage.

Example, with accessories switched off, starter and emergency switch off, unless partially shorted lamp bulb sockets you should have battery voltage...

Do I have partially shorted switches even though in the off position... Well that's a no brainer, measure the output side of these switches. Nope not leaking voltage/current through the switch... So has to be a partial short in the lamp housings somewhere right...

Now thought may be wait the regulator... Well we've already determined the rectifier/regulator charging system was to spec earlier.... Yes/No.... Hmmm...

Let's say no, regulator hadn't been tested/measured/ confirmed... Well you bypassed the coil voltage great, good spark, good eneough... Really now, this same voltage is feeding back into your regulator henceforth our statement of FIX the damn problem versus band aiding using the coil mod as a permenant fix...

All in all sure it's a pain in the ass but, one that is wise to find and correct... Or, do the mod and if it works for you and you can live with the rest, let it go and enjoy riding...

Again, it's not against the man but when the corrective answer to new ppl's question of sooted plugs & FLAT TIRES, answer always seems to be "Do the mod"...

How about, troubleshoot and correct the damn thing first and if all else fails, do the mod... :blink: :laugh:

Thanks OMR! That's good common sense advice.

I was ready to do the "mod" on my bikes, but I think I'll print your advice out, take it to the garage and get busy.

If I still don't get the correct voltage at the coils after all that, then I'll do the "mod".

No offence to anyone's preference, but it seems to make sense to me to make sure everything is clean and working properly first before attempting any mod.

Cheers

Good balanced review. Good troubleshooting approach. Fix-the-darn-problem makes a lot of sense to most, including me.

However and technically, caring the load current as directly as possible from Battery to load is my preferred method and not Kawasaki's in these bikes (probably a cost issue)... but OK, no big deal here as long as power gets to the load for the first 30 years or so. :huh:

Again technically, NOT carrying the load current through a longer than necessary wire route, more connections than absolutely necessary and more switch contacts than absolutely necessary is also my preferred method and you have guessed my reasoning... less voltage drops points and higher reliability. But OK, no big deal here either since these bikes seem destined to be on the road for decades more with or without mods.

So which method to use? Well perhaps that's the wrong question, IMHO. I my case, and this may apply to many others both with current faults or faults as yet undiscovered, I had easy access to automotive relays, wire and fuses but less access to switch gear and connector/contact parts or replacement units. So in that scenario eliminating the symptom first and working on the cause second is a reasoned approach. So is the question "where are you at when it happens, physically, mentally, parts-wise, etc."? Probably. :blink:

So no big surprise, I remain an advocate of load route management (ya, I just made that up now) so relay directed circuits remain a big part of that method for me. Therefore, I will probably continue to offer it as a solution both temporary and long term in the full knowledge that this is not the only method, that this is not a unanimous opinion and that there are strong dissenting opinions.

Completely aside, all references to WG were for historic reasons only and for the benefit of newer members only. So let's put an end to that tangent/distraction and from now on I'll simply refer to the "Coil Re-powering mod."

Best of success.
Bill

dave well said. the "coil mod " is at best a band-aid to a situation that is caused by many different things a thirty plus year old wiring being one of the main problems the simple fact is you need a minimum of at the very least 11-12 to trigger an electronic ignition system properly. if you don't have that start looking for the reason. find that repair it and you should be good to go.

893cv wrote: "just remember that you are dealing with a poor design and cheep 30 year old parts."

Man, you couldn't be more wrong if you tried! I've owned my KZ650C1 since April 1977 and have never had a problem with any of the electrical system components even after abusing them with a 100w Halogen bulb for a couple years. How could a bike with a poor design and cheap parts achive this level of reliability? Maybe you should have bought a British bike, like my old BSA, if you wanted a top notch electrical system :laugh: :laugh: Ed

650ed wrote:

893cv wrote: "just remember that you are dealing with a poor design and cheep 30 year old parts."

Man, you couldn't be more wrong if you tried! I've owned my KZ650C1 since April 1977 and have never had a problem with any of the electrical system components even after abusing them with a 100w Halogen bulb for a couple years. How could a bike with a poor design and cheap parts achive this level of reliability? Maybe you should have bought a British bike, like my old BSA, if you wanted a top notch electrical system :laugh: :laugh: Ed

Poor... Cheap...? I'm with Ed.

Sorry 893cv, the longevity of these bikes just don't support your statement. You may want to rethink or reword this.

Best of success.
Bill

BTW... We have re-named it... The Keith-1-mod... :blink: :laugh: :laugh: :laugh: :laugh:

893cv wrote:

I also recomend the coil mod, the stock ignition system should have used a power relay right from the start. OMR's advice about servicing the stock parts is important too, just remember that you are dealing with a poor design and cheep 30 year old parts.

I wish electrical was my strong point but unfortunately its not. With that being said I have the relay on two out of three bikes. I am not by any means a supporter of this mod but I have used it twice mainly because trouble shooting an electrical system to me is like watching paint dry, call it lazy or ignorant but untill i learn more on therory its the way it is. I do try to trace and fix components but my electrical knowledge is limited.

I agree that the parts are 30 years old, but I have to disagree on the poor design statement. Kawasaki has a long history of airplane and ship building which carries over to the motorcycles. I have a Suzuki GS1100 that is designed after the Kawasaki's the two are very very similar. The Suzuki to me is not as well built as the Kaws in my opinion. These are 30 year old bikes, a friend once told me "It is only a machine, fix it"

Old Man Rock wrote:

BTW... We have re-named it... The Keith-1-mod... :blink: :laugh: :laugh: :laugh: :laugh:

you can get that idea right out of your head immediately......

Nope... Sorry big man it's all yours for years to come.... :evil: :laugh: :laugh: :laugh:

Ok, let's see now... I have Steve, Plummen and now you that are driving out to AZ to beat me up.... Well I had to have some way to get us all together.... :woohoo:

The coil mod is required for:

1. Bikes left on thier side in a field for say... 19 years.
2. Persons with little electrical knowledge.
3. Just plain lazy basterds!

:laugh: :laugh: :laugh: