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 !