OzVMX Forum
Clubroom => Bike Talk => Topic started by: mx250 on December 13, 2007, 10:38:23 am
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...........Electrickity is mot my strong point ::) So forgive my ignorance ;)
Ign Coils, are they interchangable or are they model specific?
Do the brands interchange?
I ask because the Monty uses Motoplat but I have have a jap coil around that I could use.
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If your replacement coil is the same voltage input and the same impedance (measured in ohms with multimeter) then it should work. The ignition coil really is just a small transformer that takes a pulse of 6V or 12V and turns it into 25000V. A few oddballs use high voltage coils which need 400V input (Kawasaki's I think). I ran Suzuki RM coils on my Bultaco no worries
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A universal MCS coil for $20 at the local bike shop should see you right
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Beware the differance from 2 stroke to 4 stroke and from 6v to 12v
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Beware the differance from 2 stroke to 4 stroke and from 6v to 12v
ok, i gotta know what's the difference between 2 & 4 stroke coils?
this one is new to me, i understand 6V & 12V but never heard of a difference between 2 & 4 stroke ???????
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mmm..I've always assumed 2 and 4 stroke coils the same as well Hoony..they are either CD or non CD..6 or 12v..what have I missed? Normally I do try to match coils to ignitions..e.g. ND to ND coil or Kokusan to Kokusan but it's never really mattered..just me being anal ::)
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some places sell universal coils that can be for points and CDI and some sell specific ones for points and specific ones for CDI. you can also get coils for AC magneto type ignitions and DC battery-coil ignitions
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just get a MCS COIL ;D ;D
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Sorry to resurrect this one, but was is the difference between 2 & 4 stroke coils?
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I don't reckon there is one Tex. the coil impedance (resistence) just has to match the CDI output
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been down this track with my cr250
no difference between 4stroke and 2stroke ignition coils i have a xl175 new old stock coil on my points cr250
big difference between cdi and points they wont work on the other
dont know about 6 and 12v but there is adifference in point ignition depending what voltage your condencer is
jm2cw
jim
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Firstly, I apologise for being a pedantic prick!
"the same impedance (measured in ohms with multimeter) .."
"the coil impedance (resistence) "
Although impedance is measured in ohms, you can't measure the impedance of a coil with a multimeter, you can however measure the resistance, which will be a lower value than the impedance of the coil. The impedance (the total opposition to current flow) is the result of both resistance and reactance. In the case of an ignition coil, the reactance would primarily be "Inductive Reactance". Futher explanation would be to painfull to inflict upon you.
Re: 4 stroke V's 2 stroke coils, there "could" be some difference in the duty cycles for coils used on points ignitions as a 4 stroke only has to charge/discharge the coil every 2nd revolution as opposed to a 2 stroke, which has to charge/dischare the coil every revolution, however I doubt that they would bother, and the makers of the coils would just make the coils to the higher duty cycle. As a lot of 4 stroke engines with electronic ignitions fire a 'wasted spark" on the exhaust stroke, I would doubt that there would be a difference between a 4 stroke and 2 stroke coil.
Many magneto points systems do not operate on 6 or 12 volts as found with battery coil ignitions. Generally speaking if a magneto/points ignition system is quoted as being a 12V system, this is only a nominal voltage, and the voltage can rise significantly higher as the engine rpm rises.
Also be aware that many electronic ignitions operate a voltage significantly higher than 12V, most are in the order of 40 - 80V, however some do operate at voltages up to 400v.
Again, I apologise for being a pedantic prick!
CJ
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dont apologise CJ just keep going! as a qualified auto mech from way-back i am only too familiar with miss-information that was pedalled to we little apprentice types at tech about ignition systems ..the kettering system for instance "the condenser is merely an electrical shock absorber" and the common alternative of the day magnetos [unitry type] the crap the taught us didn't seem right so i made my own enqiries.however since my last day at tech was about 52 years ago the ins and outs of modern electronics is a shade mysterious although i do have 'a nuff' knowledge to get me by most times. any further tech knowledge is always welcome. cheers wally.