Topic: Coil (attachment) question...

[Zane]

I thought I'd try the suggestions at http://www.motorcycleproject.com/motorcycle/text/sohcign.html as I work through my "understanding ignition" rite of passage.  (I think I'll eventually install something electronic in my bike, but for now I'm learning quite a bit by playing with and trying to improve and optimize my points system.  I'm saving some dough too, and to be even more defensive - it's really mean weather for a while here - certainly not riding weather - so all I have to do is improve my bike and zoom around in the underground parking garage for another couple of months.  At least I have that!)

So I found a set of extremely inexpensive and lightly used GL1000 coils.  Can anyone tell me what the ceramic attachment is on the bottom of one of the coils?  Is it a heat sink or resistor of some sort (I think it is off of a California bike - ha ha), and more importantly - do I need it?  Does it even have anything to do with the coils?  (With what I received with the coils, it doesn't appear to be wired to them in any way.  It's simply attached to one coil and it has a wire running off each of the two ends of it, running parallel to the coil wires.) 

Call me confused.....

Thanks

[750goes]

Any chance of a picture to look at... might help

[Zane]

I took the GL1000 assembly apart to clean it.  Here it is sort of put back together, but not really.

Gotta have something to do with juice, since it has the ohm symbol on it.....






Hope this posting pictures business works.

Thanks!

[Zane]

Well, one worked ..... here's the second shot 750goes.

[Bob Wessner]

Hmm, sure is a strange looking thing, now I know why you posted the question. 

[Zane]

Yeah, the fact no one knew what it was right off, has my curiosity piqued.

I'll tell you that I proceeded with the gl1000 coils fitment to my '76 400f under the assumption this little piece of ceramic is something which is particular to the Goldwing.  Actually, the little metal bracket that holds this 'brick' against the goldwing coil doesnt even fit the 400 coil either. 

So my little motorcycle, for reasons I have yet to understand, runs noticably better with the gl1000 coils.  There was very little hesitation when accelerating hard with the older coils, but for sure now it's just as smooth as anything - not any sort of lag when I twist the throttle open hard at about 3500.  It just leaps forward instant like.  (I have to cut it back at about 8000 - in first - because I am in a parking garage, after all.....).  I don't know a lot about this stuff yet, but I can be pretty sensitve to machines, and this little 408 seems to be noticably happier taking it's orders from these old gl1000 coils.  Who knows though - maybe newish 400 coils would make the same improvements.  Now all I need to do is reduce the size of the electrical connections I made and to hack down the over long (for a 400) plug wires.  Thanks a lot to Two Tired, Steve D, and the others who posted about coils, plug wires and plug caps.

But I'm still interested in what the ceramic is.  I'll email some Goldwing experts (the kind that don't charge to answer questions) and see what I can determine.

[Bodi]

That's a ceramic power resistor. From the writing, 3 ohms. The power rating is probably in the 10 to 20 watt range, maybe 30 as there is a 30 in the writing.

Many cars with points ignition had resistors that normally reduced the ignition coil voltage. During starting the battery voltage would drop a lot from the starter motor load, so that resistor would be bypassed by the starter switch to give a normal or even hotter spark during cranking.

I don't know if the GL had such a system. A power resistor attached to a coil suggests something like that though.

[Zane]

Hmmm...

Do you think it would be okay to leave it off?

[TwoTired]

It is my understanding that the gl1000 coils have a lower resistance primary.  I'm with Bodi that the block in the picture is a series drop resistor.
If you measure across your coil's primary with an ohmmeter, it will tell you the resistance.  The stock coils are about 5 ohms and draw about
2.4 amps through the contact points.  Ohms law E=IxR.  If your new coils are a lower resistance, extra current will be drawn through the points.  Eg. 2 ohms / 6 Amps and 3 ohms / 4 amps.  Increased current draw will shorten point life and increase points wear leading to changes in ignition timing with use.

It's up to you to decide that more frequent points adjustment/replacement is worth the benefit higher spark voltage provides.

If you keep the arrangement, you can increase your plug gap to .030 or .032 for even better ignition.

Cheers,

[Zane]

Okay, so this little winter project is going to require a little more thought than I thought, I think.

With you guys's help I'm starting to get an understanding of how this ignition business works though - and thanks for the lessons.  (I'm frustrated by how difficult to understand I find it though.  But when all else fails the only thing I can do is persevere.  I'm pretty determined to learn it .....)

And mark up another check in the "there's no such thing as a free lunch" column.  I took those readings Two Tired, and the stock coils were just under 5 ohms.  The Goldwing coils I wired in last night (sans ceramic resistor) read a little shy of three ohms of primary resistance - maybe about 2.4 to 2.6 ohms.

I'm not sure what to do now.  Maybe I should see if I can contact the guy who wrote the "Optimizing the SOHC Ignition" article and see if he has anything to contribute.  As for deciding - the bike definitely performs better right now (as best I can tell in my parking lot course anyway).  I don't want to be always adjusting the points gap, but if I could get this kind of performance by adjusting the gap(s) every, say, 4500 kilometers or so (3000 miles) or around every oil filter change, I think that would be fine.  I wonder if there's a way to calculate approximately how much quicker the points will wear with the lower resistance coils .....

I'm also interested in pursuing the plug gap thing you mentioned Two Tired (if I decide to stick with the lower resistance coils).  It's kind of lots of fun when I do something and the machine perks up and runs more smoothly and powerfully.

So now the next question is - if I go for an electronic ignition does it function better on the low resistance coils without the (serious)drawback of burning itself up, or would I go back to a 4.5 to 5 ohm coil with an electronic ignition?

Gosh, if I had the time and resources I'd take some sort of course .....  Meanwhile, thanks a lot you guys ..... your help is certainly appreciated.

Best regards ...

[TwoTired]

An electronic trigger for the coils won't care what resistance your coils are.

Honda's interval for points inspection/adjustment/replacement was every 3000 miles.  As a guess, since you've doubled the current, perhaps every 1500 miles would be a good inspection/adjustment/replacement interval.  You could always increase the interval once you proven to yourself that the shortened interval isn't needed.

You could also experiment with wiring that resistor into the 12V power path to the coils.  This will drop the current drawn through the points and the coils.
However, if it runs as well with or without, leave it wired in and your points are as well off as they were with the stock coils.

If you decide to stay with the resistor, probably shouldn't increase your spark gap, though.

Are you using any resistors in the spark plug wiring?  Resistor plug caps or resistor plugs?

Cheers,

[bryanj]

Gl1000 uses 9v coils and that is a resistor to drop the voltage from the electrical supply (battery). The Idea is that the Wing takes a lot more starter current so the battery voltage drops and the drop at the coil is less with this system. GM used it for years on cars but there they actually had a seperate wire as well that connected the battery direct to the coil, bypassing the resistor, when the key was turned to the start position

[eldar]

If I remember, that resistor was called a ballast resistor. I dont know about the 400 but gl1000 coils were a common upgrade for the 750. From what I have read, the gl coils were a 6 volt coil but I cant remember off hand where I read that. You should be able to ax the resistor. You points will probably burn out quicker but as you are discovering, 10 bucks a couple times a year is worth the extra omph you are getting.

[dusterdude]

way to go eldy,it is a ballast resistor

[Zane]

Yeah, "ballast resistor" sounds good.  It sure is a funny little thing.  Male blade connectors coming out the far ends of a softish, crumbly, gummy centre surrounded on five sides by 6 mm's or so of fine, hard, insulator ceramic.

I like the suggestion, Two Tired, and I think I'll wire the ballast resistor into my 400 - 4 / GL 1000 system and see if I can detect any difference.  (It'll be a bit tricky because the fitment configuration that worked for the GL 1000 won't work for me - but I'll figure out something that'll get the "br" into the line.)

As for resistor plugs and caps.  The plugs aren't - (I purchased plugs a month or two ago, for my next change [due soon] and I know those are resistor plugs.  (At least they have a big R on the porcelain, which I'm assuming means "resistor".) 
I don't know about the caps.  Both sets of (4) caps are stock though, I think.  Should I not be using resistor plugs and plug caps?  How do I tell if they are?
Does the plug wire itself add significant resistance?  If it does I've got it in spades because I haven't yet trimmed down the long (way too long) Goldwing leads.  It actually looks a lot like what it is - an experiment.  And yes, it's becoming about balancing performance with a number of other factors like cost and time etc.  A year ago I would never have guessed I would become so interested in this aspect of owning a bike, but it's turning out to be a big fun part of it for me.

Finally, your advice about the plug gaps is well noted Two Tired.  If I get unsure again, or confused (almost a certainty) I'll ask.

Yeesh!  This stuff is hard for me to understand when I'm alert.  I worked outside in frigid weather all day today.  Now I've come in to the warm I can barely keep my eyes open. 

As always, thanks men - you're really helping.  Some stuff just takes me a long time to absorb I guess.  Have a great evening or day or afternoon or week-end or whatever it is where ever you are, all.)



zzzzzzzzzz..........

[TwoTired]

As for resistor plugs and caps.  The plugs aren't - (I purchased plugs a month or two ago, for my next change [due soon] and I know those are resistor plugs.  (At least they have a big R on the porcelain, which I'm assuming means "resistor".) 
I don't know about the caps.  Both sets of (4) caps are stock though, I think.  Should I not be using resistor plugs and plug caps?  How do I tell if they are?

Yes, those would be resistor plugs.  The parts counter guy sold those to you for their convenience instead of the correct plugs for your bike. (probably a stocking issue).
The stock setup used resistors in the plug caps.  I recommend you have resistors either in the plug OR the plug cap, but not both.  I don't know what arrangement the Goldwing employs.  But, you can find out. The plug caps unscrew from the wire ends.
Measure your existing plug caps input to output with your ohmmeter.  S/b somewhere around 5K or 10K for the stock 400.  I'm not sure which one of those is correct for your bike, or, what the Goldwing used.  (maybe they had resistor plugs?)

Does the plug wire itself add significant resistance?  If it does I've got it in spades because I haven't yet trimmed down the long (way too long) Goldwing leads. 

I don't know what wire you have.  It is possible to get "Radio Resistance Wire" which is usually labled as such and does have significant resistance per foot.  However, the standard wire is solid or stranded metal core.  All wire has some resistance, but at the voltages and lengths being used here, it's should be an insignificant contribution and very near zero ohms.  Again your meter should confirm this by measuring end to end.

Let us know how your experiment turns out!

Best of luck,

[Zane]

I sure will. (Let you know how it pans out.)   (And yeah, I think you're mainly right about the place from which I bought the plugs.  They're untouched as yet, so if they want any more of my hard earned dough, they'll take them back in a heartbeat.....)


I'm fuzzy in the head presently, but thanks to the generousity of others, I have all the information I need to move forward - over the week-end.  I hope I can get to the coils thing soon.  I'm distracted because zooming all around the parking garage in the middle of the night the other night I picked up a signal light screw or something like that, right through my front tire.  So now I guess before I check out the coil/resistor stuff I'll be checking out how to repair a tire.  Hey - maybe the plug guy will trade me a new inner tube for the plugs??  I want to just patch the tube but everyone I know screams "NO" to that idea.  And I should probably listen to them, for a change.

[Bob Wessner]

So now I guess before I check out the coil/resistor stuff I'll be checking out how to repair a tire.  Hey - maybe the plug guy will trade me a new inner tube for the plugs??  I want to just patch the tube but everyone I know screams "NO" to that idea.  And I should probably listen to them, for a change.

They are right, don't patch it! You are going to go through all the work anyway (not fun I found) if you do it yourself. Why take a chance on a patched tube? A new one is not that expensive and you'll have peace of mind.

[bryanj]

Putting GL coils on without the resistor will not only burn the points out but also the coils so its a waste (of coils and time)

[n9viw]

I'm curious- if the GL coils are 3 ohms, and the load resistor is 3 ohms, the result is 6 ohms. Is this too much resistance for the points, or would it somehow limit the spark energy?
I've never run 3 ohm coils on a point system, but I have heard it does cause some pitting and wear at the points due to increased current flow. But, how often do you have to dress out the points in such a situation- every 6 months? Every 3 months? How often do you dress out the points otherwise? Seems to me it would be a decent tradeoff, a little bit more maintenance for a consistently hotter spark.

[dusterdude]

i installed 3 ohm coils on my bike earlier last year,rode the bike all summer and as of yet have not had any points issues.

[TwoTired]

I'm curious- if the GL coils are 3 ohms, and the load resistor is 3 ohms, the result is 6 ohms. Is this too much resistance for the points, or would it somehow limit the spark energy?

This seems an odd question...  reminds me of the old warning sign, "Danger 10,000 ohms!"  Which, of course is a joke.   Resistance is a property.  It has no power of it's own.  However, it does interact with power in electrical circuits.  Are you familiar with ohms law?  I = E/R.

Anyway the stock coils are 5 ohm for a 2.4 amp current draw.  A 6 ohm primary would draw 2 amps through the points.  So, instead of the points handling  28.8 watts they handle 24 watts; an easier task for the points.

I gotta think the if Honda cold run the Goldwing with these coils, they would have enough spark voltage to fire spark plugs on whatever bike they are installed, even with the ballast resistor.

Certainly they will provide more spark voltage without the ballast resistor.  They will also use more power and generate more heat in the coil, too.  And at 3 ohms (or 2.5 measured), they will draw 4 amps (48 watts), or 4.8 amps (57.8 watts) and a points system will have to pass and interrupt this power, taxing them far more than the stock setup or the GL coils with the ballast resistor.

Does any of this help your understanding?

Cheers,

[jsaab2748]

Gl1000 uses 9v coils and that is a resistor to drop the voltage from the electrical supply (battery

). The Idea is that the Wing takes a lot more starter current so the battery voltage drops and the drop at the coil is less with this system. GM used it for years on cars but there they actually had a seperate wire as well that connected the battery direct to the coil, bypassing the resistor, when the key was turned to the start position

Isn't this true? I was taught it worked this way as well.  Does the resistor cut down voltage or amperage?

[TwoTired]

Does the resistor cut down voltage or amperage?

It does both.  But, it only applies to the coil's input voltage.  Two different coils can have different output voltages based on their turns ratio.  I betting that the GL1000 coils and the stock SOHC4 coils have quite different turns ratios.

Basic theory explanation.

Coil A has 1:1000 turns ratio,  Coil B has 1:2000 ratio.  Apply a 12V pulse to Coil A you get a 12,000 volt pulse output.  Apply a 12v pulse to coil B you get a 24,000 volt output.  Apply a 6v pulse to coil B and you get a 12,000 volt output, same as coil A on half the voltage.

Adjust the numbers for turns ratio and you can have 12v coils and 9V coils providing the same output voltage.

No free lunch though.  Increasing the number of output turns adds more wire resistance, reducing the power output.  The same effect can be achieved by reducing the number of input turns.  However, this lowers the resistance, causing more current to flow through the primaries.

There are a LOT more details.  Anything specific you need clarified?

Cheers,

[oldfart]

I thought I'd try the suggestions at http://www.motorcycleproject.com/motorcycle/text/sohcign.html as I work through my "understanding ignition" rite of passage.  (I think I'll eventually install something electronic in my bike, but for now I'm learning quite a bit by playing with and trying to improve and optimize my points system.  I'm saving some dough too, and to be even more defensive - it's really mean weather for a while here - certainly not riding weather - so all I have to do is improve my bike and zoom around in the underground parking garage for another couple of months.  At least I have that!)

So I found a set of extremely inexpensive and lightly used GL1000 coils.  Can anyone tell me what the ceramic attachment is on the bottom of one of the coils?  Is it a heat sink or resistor of some sort (I think it is off of a California bike - ha ha), and more importantly - do I need it?  Does it even have anything to do with the coils?  (With what I received with the coils, it doesn't appear to be wired to them in any way.  It's simply attached to one coil and it has a wire running off each of the two ends of it, running parallel to the coil wires.) 

Call me confused.....

Thanks

Hi.  That's my website, and I wrote the article.  My email address is in the article, feel free to use it.  Contrary to what you have read on this board, using GL1000 coils will not hurt either the points or the coils.  The resistor looks like a ballast resistor, designed to shift available voltage away from the low rpm range and up into the higher rpm range where the points ignition type systems tend to run out of voltage.  Old cars did this.  However, as has been pointed out, the Wing used the resistor in a different way, in much the same way that the old air-cooled VW engine used it -- bypassed for starting through the coils direct for more voltage, then through the resistor during running.  Remove the resistor.  Even on the Wing it isn't useful.  The coils will work just fine without it. 

Okay, now my soapbox.     Now, a lot of Internet "experts" will tell you how wonderful Dyna or Martek or other points replacement systems are.  They insist they are better than the points system -- better in any number of ways, etc.  In reality, none of the simple points replacement systems (as differentiated from the more sophisticated complete systems such as the Dyna 2000, Dyna 3000, MSD, Gerex and others) offer *any* advantages other than reduced maintenance.  They don't have hotter sparks, they don't offer increased timing accuracy, and they don't use less current, than the stock system.  They couldn't, since they only replace the points with a pulser and a transistor, just like the system Honda went to in 1979.  Additionally, many will argue that since the reason Honda and other manufacturers went electronic in the late 70s was to meet increasing emissions standards, then these systems *have* to be betteR.  Not so.  What these folks fail to understand is that the new emissions regulations that appeared in 1978 brought with them a new kind of warranty, an emissions warranty, with longer terms than the then-standard 6-mo warranty.  The result was that maintenance items were added to the warranty, and because points couldn't go 18,000 miles (the actual spec is 18,641) without being adjusted, they had to go.  That is what necessitated the advent of electronic ignition in the late 70s for motorcycles, not any increase in quality.  Of course, today things are much different.  The electronic ignitions used today, with few exceptions, bear little resemblance to the simple points replacement systems of 1979.  They *are* much better, but that is a whole different subject.  :-)

Mike 

[Zane]

Okay, so here it is.  I dusted the ballast resistor, locked in the GL 1000 coils, swapped the plug caps that came on the GL plug wires with my stock 400F plug wires, and cut down the super long GL plug wires to the same length as was on the bike with the stock 400 coils.  It looks the same (pretty much) as it did before (except for the different rating numbers on the coils themselves). 

I'm amazed how smoothly and powerfully the engine is running.  Time will tell if that situation holds.  It feels awfully good though.  I guess the worst that can happen is I lose my twenty-five dollar investment in the coils and points.  It sure doesn't seem as if that's a liklehood right now, but one never knows i suppose.

Thanks for the excellent discussion everyone.  I like to think I appreciate all points of view, and I know I appreciate the informed and well thought out answers consistently given by Lloyd, Mark, Mike, Bob and the others.  And not only here, but on other topics too.  I didn't know how the plug wires and the plug caps worked until I read other topics.  That info enabled me to do this little modification.  So thanks for all that too.

Be well All,

Bill