Author Topic: Repowering coils via a relay  (Read 1989 times)

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Offline hahnda

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Repowering coils via a relay
« on: December 20, 2006, 06:32:34 AM »
Was wondering what thoughts anybody might have on this.

http://www.wgcarbs.com/59021.html

I've used a similar method to brighten up headlights with good results. Seems like it might be worth a try.

Kevin
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Offline SD750F

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Re: Repowering coils via a relay
« Reply #1 on: December 20, 2006, 06:46:30 AM »
This is a great idea! You will eliminate any power loss in your ignition switch, as well as the wiring harness and connectors that take the power from your battery, through your ignition switch, and back to the coils with a couple barrel and spade connectors on the way.

Scott

P.S. Check out my Tricks & Tips on Electrical Overhaul http://www.sohc4.us/forums/index.php?topic=15885.0

Offline burmashave

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Re: Repowering coils via a relay
« Reply #2 on: December 20, 2006, 08:45:32 AM »
Makes sense to me, too.  I may try it if I have time to rewire my bike this winter.
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eldar

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Re: Repowering coils via a relay
« Reply #3 on: December 20, 2006, 09:24:19 AM »
this is already in the faq section.   cben already wrote something on this.

Offline TwoTired

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Re: Repowering coils via a relay
« Reply #4 on: December 20, 2006, 09:31:06 AM »
If there is a pot hole on a bridge slowing traffic.  Would you?
A) patch or repair the pot hole.
B) build a new bridge next to the old one then condemn and abandon the pot holed bridge.

If you are a politician or government employee, or have a lot of someone else's money to spend, clearly, (B) is the correct choice.

Both dim headlights and spark issues can have lowered voltage as a cause.  The voltage loss is usually caused by connectors and switch contacts getting corrosion or other high resistance material placed in the electrical path.  There are lots of connectors and connectors on the bike. And, if the headlight or ignition path has the problem, it is most likely endemic to the entire bike.  Bridging around each one strikes me as rather silly.  Since you will in essence be replacing the entire wire interconnect system of the bike.  You will still have charging deficiencies before you complete the whole task, as each of the remaining corroded connectors passing current still throws away power from the charging system as heat.  This power, saved, will make your battery recharge faster, your headlight shine brighter, and your coils more eager to spark.

The headlight and coils worked just fine when the bike rolled off the showroom floor.  The wiring is tired after all the years and exposure to the elements.  Tune up, repair, and restoration will work wonders.

The "add relay" mentality seems to be like saying.  Gee, the compression is down on the engine cylinders.  Lets add another engine to the bike in parrallel to bring the power back up.

Fortunately, a relay IS smaller.  And, lots of people kludge things onto their bikes, leading to following owners to exclaim (What the $#@!!!)

Someday, I am going to see a bike completely finished with bandaids.

Cheers,







Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

eldar

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Re: Repowering coils via a relay
« Reply #5 on: December 20, 2006, 09:40:17 AM »
I have seen close with the seats duct taped.  On a stock bike I would have to agree. however if a person gets hotter coils but for whatever reason is unable to get a dyna or some other elec ign, then this would allow the coils to work closer to their specs. Of course your charging system has to be up to snuff in the first place.

Offline Steve F

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Re: Repowering coils via a relay
« Reply #6 on: December 20, 2006, 09:42:48 AM »
If there is a pot hole on a bridge slowing traffic.  Would you?
A) patch or repair the pot hole.
B) build a new bridge next to the old one then condemn and abandon the pot holed bridge.

If you are a politician or government employee, or have a lot of someone else's money to spend, clearly, (B) is the correct choice.

Both dim headlights and spark issues can have lowered voltage as a cause.  The voltage loss is usually caused by connectors and switch contacts getting corrosion or other high resistance material placed in the electrical path.  There are lots of connectors and connectors on the bike. And, if the headlight or ignition path has the problem, it is most likely endemic to the entire bike.  Bridging around each one strikes me as rather silly.  Since you will in essence be replacing the entire wire interconnect system of the bike.  You will still have charging deficiencies before you complete the whole task, as each of the remaining corroded connectors passing current still throws away power from the charging system as heat.  This power, saved, will make your battery recharge faster, your headlight shine brighter, and your coils more eager to spark.

The headlight and coils worked just fine when the bike rolled off the showroom floor.  The wiring is tired after all the years and exposure to the elements.  Tune up, repair, and restoration will work wonders.

The "add relay" mentality seems to be like saying.  Gee, the compression is down on the engine cylinders.  Lets add another engine to the bike in parrallel to bring the power back up.

Fortunately, a relay IS smaller.  And, lots of people kludge things onto their bikes, leading to following owners to exclaim (What the $#@!!!)

Someday, I am going to see a bike completely finished with bandaids.

Cheers,








While you may think it's silly to add a relay, think of the path that the power must take for say, the headlight.  From the battery, through the ignition switch, through the starter button (if it's an "always-on headlight"), through many miscellaneous connectors, and not to mention some rather questionable wire gauge.  Adding a relay to my headlight circuit has without a doubt increased the brightness, as well as decreased the likelyhood of trouble due to connectors failing.  I can proove that the relay has made the headlight more efficient.
That being said, I would definately go ahead and do the same for the ignition circuit.
Yes, while the factory system "worked", there was always room to improve what Japan offered at the time.

eldar

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Re: Repowering coils via a relay
« Reply #7 on: December 20, 2006, 10:49:15 AM »
steve, tt is a stocker. he likes things to be stock and stock cannot be improved upon. It is not just the ignition, it is most everything on the bike. he is a very good source of electrical info but is in almost every case, inflexible on even considering mods. That is just him.

Personally, I would build a new bridge bigger than the old one! ;D

Offline TwoTired

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Re: Repowering coils via a relay
« Reply #8 on: December 20, 2006, 12:48:07 PM »
While you may think it's silly to add a relay, think of the path that the power must take for say, the headlight.  From the battery, through the ignition switch, through the starter button (if it's an "always-on headlight"), through many miscellaneous connectors, and not to mention some rather questionable wire gauge.  Adding a relay to my headlight circuit has without a doubt increased the brightness, as well as decreased the likelyhood of trouble due to connectors failing.  I can proove that the relay has made the headlight more efficient.
That being said, I would definately go ahead and do the same for the ignition circuit.
Yes, while the factory system "worked", there was always room to improve what Japan offered at the time.


Oh, I'm well aware of the electrical path and it's capability.  The engineering of the original components was pretty good.  Did they spare no expense, and wildly over design?  Of course not!  They had to keep the total costs down.  And, not many buyers would appreciate or want to pay for gold plated connectors and switch contacts that would last 10 times longer than the ones Honda incorporated.   But, the original electrical components were/are more than adequate for the task.  IF the wire is not damaged, the crimps and connections are clean and tight, and the switches aren't worn and corroded, the voltage at the headlight is never more than 0.5 volts down from that of the battery.  For the stock 50W headlamp, that's a loss of 2W capacity and even less on low beam.  Certainly if you are losing 1 or 2 volts delivery to the coils, there is a problem.  And, yes, wiring around the problem will make the voltage higher.  But, it is still sidesteping the problem rather than repairing it.  And, such a voltage loss problem speaks loudly that other areas of the bike wiring are in need of attention and repair as well.  If you choose not to attend to these, it is your choice to make, of course.

I'd like to know how you calculate the "questionable wire gauge".  I've never noticed any heating effects on the stock wiring for the 4 or 5 amps passing through the headlight wiring.

Of course, if you put searchlights on the front of your bike, the amperage will go up, and you will need to re-engineer the power distribution.  Failures of the original components with such modifications are not the fault of the original engineers, but those of the modification engineers and their lack of understanding about how the original components are capable of performing.

Cheers,








Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Steve F

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Re: Repowering coils via a relay
« Reply #9 on: December 20, 2006, 01:14:32 PM »
TT, no offense was meant, and I certainly respect your knowledge of the SOHC and electronics / electricity, and wasn't trying to discount your input.  I was just trying to make a point that while I have painstakingly gone totally through all of the wiring and the connections and switches, etc. on my cafe'd bike, I have come to the conclusion the the installation of the relay has helped handle the headlight current better.  The lamp is brighter, and reacts much faster to high-low beam switching.  I "over-engineered" the wire gauge to 14ga., and wired the relay in series with a fuse directly to the connection at the starter solenoid.  I'm just stating that it works great for me, and that all the extra circuitry length that Japan used while building these bikes can be made shorter and more direct.

Steve F

Offline mwvachon

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Re: Repowering coils via a relay
« Reply #10 on: December 20, 2006, 06:18:00 PM »
OK - I just have to chime in here, even though I'm no electrical genius. I read over the design for the repowered coils and was a bit intrigued by the concept. However, I'm with TwoTired on this one. My own K1 is exhibiting the same symptoms described (headlight brightness tied to RMPs, turn signals that won't flash at idle, and popping/backfiring when rolling off the throttle) - but I'm going to follow the 'Three phase charging system inspection and maintenance for all pre 79 SHOC4 motorcycles' instructions [posted on this site] and stick to an OEM configuration. I didn't spend all my time and effort to bring back this splendid Honda to it's original state to even consider the notion of tacking on various fix-it patches. All original or nothing for me. OK, OK... I confess to swapping out the cursed Philips screws for the hex-head engine bolt kit - but that's it, honest! But that is strictly my own vision. I heartily sympathize with the folks here who just want to ride a vintage machine and apply what ever updates that makes their own use and maintenance more trouble free - OEM correctness be damned! I also was unable to find any hand controls and was fortunate enough to cobble together the correct parts from several junk controls. I have a spare K1 motor and am toying with the idea of building a whole 'nuther bike with it. Most likely a custom. It would be great to be able to use all current generation hardware instead of haunting well-picked-over bone yards for critical parts. Keep those re-engineering ideas coming, seems there's a fair number of customizers who can use them. As for the purists on this site, do the same with the regular maintenance stuff. It's just as vital to those of us who continue to come back for those hard-to-solve issues.
M.W.Vachon
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1971 CB750-K1 (Candy Red)
Project link: http://forums.sohc4.net/index.php?topic=108498.0]
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Offline cben750f0

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Re: Repowering coils via a relay
« Reply #11 on: December 20, 2006, 08:30:23 PM »
dont worry twotied didnt like when i did it either....


NEway, yeah it makes a difference.... and can be put back to stock in seconds if you do it correctly.

peace

 and here is another thread on it... peace

http://www.sohc4.us/forums/index.php?topic=8878.0
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Offline hahnda

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Re: Repowering coils via a relay
« Reply #12 on: December 20, 2006, 08:43:10 PM »
Well it looks like it will be the way I wire mine up. I don't have a wiring harness to begin with anyway. I'm building a CB500 cafe and it seems like the way to go. Thanks for the links to your posts cben750f1.
Kevin
CB750K4 in pieces
CB750K3 with F trim
CB750K7
CB500 Cafe Project
CB750 Cafe