Weak spark.

I want to keep this separate, as not to completely mess up the ongoing thread regarding the poor spark.

I'm having a problem with this whole "coil/ballast-resistor/total resistance/operating voltage" topic.

My understanding of the purpose of a ballast-resistor has always been to have a coil that will produce a plentiful spark at a lower battery voltage such as when starting the vehicle. Engine designers recognised early-on that the voltage drops substantially when the starter is engaged and if a coil were designed to produce a healthy spark effeciently at "12" volts, then it certainly can't do the same when the voltage drops significantly during starting. So they designed the coils to operate effeciently and effectively at 7-8-9 ? volts - the available voltage when the starter is pulling the battery voltage down. Once the engine starts the charging system is now operating at 12.5 -13.5 volts which would certainly over-heat the coil(s). SO, a ballast-resitor is place in series with the coil power supply to maintain the nominal design/operating voltage (7-8-9 ? volts) of the coil. The difference with a car (a car with a standard ignition system) as opposed to our bikes is that with a car; when the key is turned to "start", the ballast resistor is by-passed so the coil(s) can get ALL the voltage that is available for a good "starting" spark. When the key is returned to "run", the "run" circuit now includes the ballast-resistor to protect the coils. The short "start" time has no appreciable negative affect on the coil(s). Our 1300's do not have a "starting by-pass" circuit (for reasons I can't explain?) but came with a ballast resistor which (in my mind) suggests that the coils are designed to run on much less then 12volts, for the same above reason. To provide adequate spark during starting.

If a coil is advertised as a "12 volt" coil, is the "12 volt" rating a general term to differentiate it from a 6 volt system ? Regardless: Does a "12volt" rated coil need 12.5-13.5volts as supplied by the charging system or does the 12 volt rating refer to the coil fitting a 12volt system (but still requires a ballast resitor to protect it?) I've always believed the latter.

Then we get into the "Total Resistance" question. I'm lead to believe the resistance of the coil is a requirement for the coil to produce it's maximum spark with the lesser voltage. Less resistance - more spark? That's where the debate gets heated (no pun intended) over whether a few ohms resistance difference will "burn-out" the ignitor.

The next question is: What is the manufactuters "intended" rated operating voltage of the KZ1300 OEM coils ? Does ANYONE REALLY know ? "12" volts? 9 volts, 7 volts? My uninformed impression is that our coils (and the igniton trigger controller system was designed to operate on much less then 12 volts for "starting" purposes and when the charging system is running the ballsat reistor closely maintains this voltage for the protction of the coils.

GM coil-pacs as well as other aftermarket coils have various resistance ratings. I am presumming the varied resistance ratings are to match the various and more technically complicated computer controlled ignition systems. Why the varied resistance ratings? My rationelle suggests, it's because it's easier to make a coil to match a computerized ignition system (and it's unique and specific requirements) then it is to make that computer match a coil.

There's been so much dialogue, controversy and hypathetical analysis of the "coil" topic, I simply have gotten lost in the retoric. In my mind, unless someone can relate to the "absolute" values and the "allowable tolerance of those values", it's ALL conjecture based on what we think we know and how that guesstamation is interpreted and applied.

Add to the mystery of all of this; the someone with a problem who doesn't know whether their ballast resistor is in the circuit or not, doesn't know what it looks like, can not use a multi-meter correctly and therefore can not provide a reasonably solid background of correct self diagnosis which when is put to incorrect wording, only confuses the problem even more and makes any rational attempt by others to solve the problem - almost endlessly impossable to rectify ( no pun intended here either) !


What am I missing here, with this "use this coil, use that coil, coil total-resistance/balast-resistor in or out of circuit" theory stuff ? I get the "V" and the "I" and the "P" and watts and ohms stuff ! I just can not seem to get my head around all the stuff that everyone is claiming to be correct when in reality only ONE answer should prevail. PERIOD !

I've been using a GM pac WITH the ballast resistor, trouble free for years. And the spark will knock me on my ass ! Haven't burnt out anything. It starts with key ON and stops with key OFF. Plugs are great and nothing's melted.

I think I'm going to stick with re-building that Mikuni stuff and making those floaty things! That's stuff I know and understand ! Carbs are easy !

Thank You ! Whew ! :side:

Here, here !!!, I ain't got too much education, turn key on, hit start .. motor runs, don't care about this and that, put those yellow coils in (excel ??) , they work, took ballast out of line, I try and stay away from tech discussions as it's way over my head, give me a hunk of fencing wire and a screwdriver or two and I can get it going, good luck to all who understand it, i'll just keep muddling along, all my stuff ain't pretty but it gets me from "A" to "B" without too many break downs

I hear what you're saying Scotch. It's not easy to discern. I've always believed in the KISS principal (Keep It Simple Stupid). When Kawasaki designed /built the bike it ran like a dream right? Then what? lack of maintenance, attention to detail, part time use, stored in humid or outdoor storage? How does one get from a decent running bike to one full of problems? People tend to look for the ultimate fix and will spend big bucks to fix it once and for all when they should stay focused on the KISS principal and look for the obvious and correct. Corroded connections are almost always the culprit but can cause other electrical components to fail and not all electrical failures are easy to spot. Your right, just having a multimeter doesn't mean you have all the tools to diagnose. Not having a schematic of a control module and a sound understanding of electronic circuits and you may as well beat your head against the wall.

When I first started out as a auto mechanic I was basically taught breakdown maintenance. Customers would come in with a problem 9it's broken) and we'd fix it. Then we started to graduate to preventative maintenance where we fixed the car and did a cursory look around and found things on the car which would fail shortly- brakes , shocks, mufflers etc.

Then I moved out of automotive and into nuclear power generating. Breakdown maintenance happened granted, but our regulator spanked us for that and told us we should have caught the failure before it happened. Hence the preventative maintenance program took a leading role in the maintenance program so we wouldn't get spanked so often.

Next, our Engineering Dept took a leading role and started to track the failures and started a maintenance monitoring program to look for trending issues and "Predict" when the next failure would happen and schedule maintenance to replace the component before failure and this is the level of maintenance I tend to use to look after my equipment. And it's a simple process to follow.

It requires an inspection program and before inspecting you need to clean. That's why the most important job on the racing team is the guy on the end of the rag. He'll find the loose bolt on the race car that could have lost you the race. Observation during cleaning is critical. Once it's all clean start a methodological inspection and that can only be done through a creation of an inspection sheet.

You talked on a previous thread about pulling your carbs apart once a year and cleaning. That's predictive maintenance. had you noted that on a certain occasion when you pulled them apart, they were spotless and nothing needed to be done and you decided to increase the inspection interval to every 2 years, that's monitoring and adjusting your predictive maintenance program. Now we're into Adaptive Predictive Maintenance. It's all good stuff.

Imagine if you will what would happen in the airline industry if they operated at the breakdown maintenance, or preventative maintenance level. We'd have plane falling out of the sky. Same with the Nuclear Industry. One fatal mistake and we'd have another Three Mile Island or Chernobyl.

I've learned a lot over the years and love to share and that being said, I still have a lot to learn and hope I never stop. That's why I love bantering stuff around here!!

Well put, kawboy ! The "predictiva/adaptive" maintenance remark is perfect.

" I do hereby pledge to do my very best not to "go Chernobyl" on any topic taking-up less then 12 pages."

"Let that page-count not be less then 12, nor shall the page-count be that of only 12. Thusly if the page-count exceeds 12, let not me "go Chernobyl" 'til the arrival and full completion of the 13th page".

so it is written........

Scotch, you are overlooking that the old-school ignitions used straight 12 volts to drive the coils. Our bikes, as well as all modern ignitions, use a form of capacitive discharge to drive the coil, so all of that ballast-resistor-bypass stuff and voltage drop doesn't exist anymore. The ignitor, which is a capacitive discharge system, has output voltage regulation so that no matter what the input voltage is, it will always have sufficient discharge to the coil to do the job. If the input voltage drops from cranking drains, then it simply increases the current to maintain a constant input WATTAGE so the output voltage stays the same. Don't forget, a CD system bumps the discharge voltage up to around 400 volts. With it's built in voltage regulation for that discharge voltage, input voltage isn't important as long as it's within operating range, which is a very broad range. Probably from around 6 volts up to maybe 17 or 18.

But, EXCELLENT question! And, it fits right into what I will be discussing soon.