GM HEI: Cheap and Extremely Effective Ignition Upgrade

If it's broken or just needs tweaked

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Deepseamdv
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Joined: Wed Dec 21, 2011 10:55 pm
Location: Northern California

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby Deepseamdv » Fri Jan 06, 2012 2:52 pm

I cut the wires to the ignition modules but installed bullet connectors. The bike only has 9k original miles so the wire colors are still pretty good. I'm going to go back through everything today with the new info you've sent. I'll let you know what happens later today.
Thanks

Deepseamdv
Posts: 5
Joined: Wed Dec 21, 2011 10:55 pm
Location: Northern California

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby Deepseamdv » Sat Jan 07, 2012 11:38 am

I put everything back to stock and now have a very weak spark at all 4 plugs. For just a few seconds #4 had a good strong spark but it didn't last long then became weak again. I found the wire harness ground and cleaned it but it made no change.
The original problem was that after a few minutes (anywhere from 10-30 miles) the bike would loose power, #1 & 4 stopped firing. Waiting 30 or so minutes and it would run again. Sometimes it would run for several days other times not at all. The last time I rode, it lost power then stopped running completely. A man I had never meet (another combat vet and biker) stopped then went and got his trailer and took us home, some 25-30 miles. I have already sold this bike but will not let it go until I know it is running ok. The local M/C junk yard wants $150.00 for the ignition modules with no guaranty & no return.
Any idea what will cause such a weak spark? I've changed coils, plugs, plug wires and checked most if not all wire connections.
Next I'm going to re-install the relay to provide 12vdc direct to the stock coils. After that ???

SchoolDaGeek
Posts: 147
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Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby SchoolDaGeek » Sun Jan 08, 2012 11:29 am

These are the same problems I have run into, esp. with the 4 prong modules.

The stock coils are only capable of a mean of 9kv when running, whereas the DIS ignition can produce 50-70Kv. It is possible the one coil that is shutting down is becoming overheated, which means it is likely out of spec. or something is happening with dwell feedback that is sending the temp. higher on that side of the ignition.

Ebay is a much better source for used equipment, still no guarantee but I have found voltage rectifiers and Ignition modules for $15-$20.

Also in my experience the stock charging system is just not up to par, and your 10-30 mile range depending on whether it is highway or city could be having an effect on your available charge.

Two things I would do, use a handheld impact driver (manual is fine, the kind you hit with a hammer) with a #3 Philips bit, and remove your reluctor advance. Check behind it, clean everything and lubricate, re-measure your gaps to .2-.6mm, reassemble, and then perform the Static alignment in section 3-4 of cosky0.tripod.com.

The second thing I would do is put a voltmeter on your battery and hit the start button. If you are dipping down to 5v at start, your battery is likely on it's very last leg, which indicates problems with it and your charging system. I've only had moderate success when it dips in the area of 9-11v, and definite problems once it goes under 8v. There are also new ignition switches on Ebay that would save you disassembling and cleaning those contacts from $15-$25. The $15 ones save your key, the $25 ones com with the entire cylinder and new keys. This could be providing resistance to the circuit that as the voltage rises off the rectifier, the resistance creates heat, and a false reading to the rectifier and it may be boiling your battery, which gives "great charge" but harms the battery and vents out all the liquid so that your 10-30 mile range then a cooldown would be returning the battery to a more cooler/settled state.

If you have the money and time, I would look into Pinhead's cheap Ford regulator and 3 phase bridge rectifier, either off of Ebay or from westfloridacomponents.com.

Also make sure you are using copper core ignition wires, not resistor core. New Hypalon copper core is sold by the foot on Ebay as well as many auto parts stores, but is difficult to find stores that still have spools because they take up space.

I'm with ya brother! Hopefully together we can solve our extremely similar dilemmas
Last edited by SchoolDaGeek on Mon Jan 09, 2012 11:10 pm, edited 1 time in total.
Buy New, Wire Right. BNWR. LOL

SchoolDaGeek
Posts: 147
Joined: Fri Aug 26, 2011 8:36 pm

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby SchoolDaGeek » Mon Jan 09, 2012 1:04 pm

Have some more info that may be helpful.

Because my last attempt seriously overheated the modules, and I was jumping off a car battery, I remembered Lou's description of the positive DC feedback, and wondered why the voltages were off so much that they were loading the modules with the full 5.8 amps @/or 6+ volts as they climbed.

I switched gears and just started looking up the OKI MPS-200 module on Google. I also had a question on what was the GM coil matched to the original 4 prong, at least on one application.

I looked up a 1980 Corvette with a 5.0L, and it has the 4 prong module with a slightly different coil due to the fact it is sitting below a 8 cyl distributor cap. It has 3 wires out and a common coil terminal.

http://www.rockauto.com/catalog/moreinfo.php?pk=935138

You can see that the primary and secondary measurements are "OK" up to a .1 and 1k Ohm difference than the C849 coils.

I tried to look up how the Corvette was wired, but I could not find it. I did find wiring diagram for a 5.0L Bronco.

Image

In this diagram, you can see that the black middle wire (probably) goes right to ground, as I would not expect anything else for a black wire with an eylet on it to be put except under a metal screw. This kind of goes along with what we know about the DIS type ignition, that when the double coils we are using fire, one spark goes the "proper" way from electrode to ground, but the charge coming out of the opposing Secondary terminal jumps the other way, from ground to electrode, which is what causes the wear. The other idea I had is that maybe it goes to an isolated resistor block that filters the signal for the tachometer and engine control feedback (like the 7 prong modules have for EST). The other thing I found in the schematic is that this particular setup uses a start ballast resistor. When the ignition button is switched, full power is given to the coils, but there is a ballast resistor that is in between two closely spaced wires to the module for power. This would mean to me that the ignition module is getting either half or double the voltage as per here:

http://moodle.student.cnwl.ac.uk/moodle ... istor.html

Since I was looking up the OKI MPS-200, I did come across two schematics of an 82 and 83 Honda Goldwing 1100, BOTH which have ballast resistors right on top of the coils.

http://goldwingchrome.com/Manuals/GL110 ... ematic.jpg

http://goldwingchrome.com/Manuals/GL110 ... ematic.jpg

Which I verified on Ebay as well as searching for the OEM measurement, which turns out to be 3 Ohms @10%.

The Goldwings have a different firing order, 1,2 and 3,4. As we know, no one has ever complained about a Goldwing 1100 being a "cold hearted beast" to start like the 650 is. Nevertheless the ballast resistor is there. My suggestion here is that just like my 81 Suzuki, it would seem easier to get a bike started if at least one of each side fired correctly, meaning it would be theoretically possible to get started with 1 or 3 WITH 2 or 4 than our 650s are, this is because the two spark events happen next to each other which has more inertia. But yet the Goldwing and at least one Bronco out there use a low Ohm ballast resistor to "equalize" the voltage across the system, but is bypassed on start for the Bronco, and is "on all the time" for the Goldwing.

I also found another site that would confirm this:

http://www.network54.com/Forum/47850/me ... n-+HOW+TOO

But because of the high-end "Touring" characteristics of the Goldwing, it is confirmed that once the GM 4 prong is used instead of the MPS-200, this ballast resistor can be removed.

So I am wondering now...Maybe the low resistance GM coils NEED this ballast during the start phase. Instead of trying to calculate across a 530 +/- 50 Ohms on your reluctor side, why not put a 3 Ohm Wirewound resistor (or an original Goldwing Ballast) on either the coil side or the module side?

I am still using a second relay trying to "break ground" to the reluctor negatives as two of the early attempts only got the bike to start by breaking ground reference with the white wires.

Instead, I could switch this relay to feed off the coil relay for the through voltage, which would completely skip any corroded ignition/starter switch resistance (which is sending the modules into feedback/infinite dwell) and apply battery voltage minus 3 ohms of ballast to the modules (as appears to be in the Bronco) then when the motor catches and the starter is released, the 3 Ohms of Ballast feed the coils.

So in fact, we isolate both circuits from the white/black ignition wire altogether, and only power the relay with the white/black wire, and use the starter button to interject 3 Ohms of resistance either to the coils AT START or RUNNING (which would begin to use the current limiter in the modules if primary resistance then became 3.2-3.7Ohms) or ONLY for the modules, which if wired similarly to the Bronco, for example, the MODULE would also receive half/double/nominal voltage at start, but then would revert to full voltage (albeit switching the ballast to the coils)

I hope this helps! It makes sense to me in my mind. Please notice that in the diagram of the GM Module on the 1100, he also only uses W being fed by the positive side of the reluctor, but simply grounds both whites. He also does not address the green wire harness ground, and ONLY uses the heatsink bolted to the frame as ground, leaving G unconnected on the module and no harness ground (which is kinda sorta like 'breaking ground')

So then on the four prongs, we can take the white wires of the harness and just jump them to the green wires, but keep them off of the heatsink ground, add a proper ballast of 3 Ohms to seriously increase either the starting voltage, and/or regulate the running voltage (as on the stock Goldwing with the MPS-200 and identical coils).

It would seem easier in theory to me. The Goldwing is going to have a higher output Amperage for all the lights, radio, cb, and accessories, let alone turning an 1100cc motor, as well as a higher CCA battery to start with compared to the CB650...
Buy New, Wire Right. BNWR. LOL

Pinhead
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Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby Pinhead » Mon Jan 09, 2012 5:19 pm

I'm afraid you're severely over-complicating things.

The reason the original GM design uses a ballast resistor is due to the produced dwell at running RPM is "too long" for the coil they were using.

With the reluctors on our Hondas, the produced dwell is constant regardless of RPM throughout the rev range (only the amplitude of the signal changes). Due to signal attenuation at low RPM, the modules requires a "boost" during start.

If your modules are overheating at all than your dwell is too long which means you have the modules wired contrary to the original diagram. The test system that Lou used for testing is identical to what we're working with, provided you have it connected correctly. There is no difference.

With a jump-start from a running car (and battery voltage staying pretty constant above 13v at start) you shouldn't even need the boost circuit. If it doesn't spark when you're cranking it with a jump-start, you either 1) Have it wired incorrectly or 2) Have a fault in your harness. There is no other explanation (though, by wiring it incorrectly you destroyed your components).

The easiest way to eliminate the harness variable is to attach the positive voltage source (for the coils and the modules) and ground directly to the battery terminals. Then run the "negative" side of the coils directly to their respective terminals on the modules.

The only variable left is the connection from the reluctors to the modules which is easily measurable and verifiable.

SchoolDaGeek
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Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby SchoolDaGeek » Mon Jan 09, 2012 9:36 pm

I like it when you talk dirty to me, Pinhead!

Where was that wisdom pages ago?
That is wisdom, folks.

Let me pitch spark/flame theory on you now...I have extended tipped NGK #5829 - DP8EA-9 that are cheaper, more available, and come factory gapped to .9mm.
Buy New, Wire Right. BNWR. LOL

SchoolDaGeek
Posts: 147
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Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby SchoolDaGeek » Mon Jan 09, 2012 11:34 pm

All you get from an Osilliscope is to tell you where you have been wrong.

If this ignition is to get running on an poorly cared for CB650 from 79-81 no matter if it was a custom, or it was an 1100 Goldwing,

Honda used the same parts.

GM used the same parts as well.

First order of business before attempting this "MOD" is to open your reluctor case on the right side, you will need an impact wrench, manual, air or electric.

You will need a deep well #8 Metric and a good impact driver fitted with a #3 Phillips.

Remove the RELUCTOR WELL and clean it the best you can with solvents and brushes. Finish with lubricants. Continue bitching on the forums. Don't get your laptop greasy.

)
Buy New, Wire Right. BNWR. LOL

Loudhvx
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Joined: Tue Aug 23, 2011 5:51 pm

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby Loudhvx » Fri Jan 20, 2012 3:09 pm

Sorry to take so long in getting back to this, but for some reason, this fall/winter has been very busy with all sorts of ignition requests.

Schooldageek, sorry you are having so much trouble with the mod. There are plenty of examples of it working on other CB's. That is, the 4-pin module with GM coils. The circuit using factory coils is not confirmed to work, which is why I labeled it as "proposed".

Yes, it would have been better if I had an actual CB to do the testing on, but mostly better for me, since I had to spend countless hours corresponding with CB owners about what their bikes were doing and how they responded to changes in the circuit. But luckily, the ones I corresponded with were very patient and diligent which actually makes it a pleasure to deal with, and quite satisfying.

I did not make this mod for the sake of making a mod for a bike I did not own. It was made on the request of several CB owners. I made the original mod for KZ's, since that's what I own.

Because I did not have a CB to work with, the only wiring identifications I could give were the ones that were attached to the parts I received from CB owners to do testing on. The wiring colors chosen by Honda are unfortunate, as is the practice of using an easily-removable plastic band to differentiate wires of the same colors. I could only specify the wiring on the parts I had knowledge of. The rest would be up to the user to identify.

Reading over the last several pages, I am indebted to Pinhead and Volker, as their posts have been exactly right. From what I recall, even their speculations were accurate.

If you are getting no spark at all, then there is clearly some fundamental thing that is not in order. Such as a missing ground, or major wiring mistake, or bad components.

One simple test you can do is to simply connect and disconnect 12v to the G terminal, briefly. If that action does not generate a spark, then there is a major, fundamental flaw somewhere. Not a minor one related to dwell, start-boost etc.

Deepseamdv
Posts: 5
Joined: Wed Dec 21, 2011 10:55 pm
Location: Northern California

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby Deepseamdv » Mon Jan 23, 2012 3:16 pm

Here is what I ended up doing after being unable to make this mod work on my bike. Everything is back to stock. I purchased a set of after market Procom igniters, p/n PEC-C-MH900-A on Ebay for $79.95. The price included shipping from Oklahoma City,OK. The company is Hillery Vending, 10400 Schwartz Dr, (405)496-5263.
The bike started on the first try after sitting for 8-10 days and idles very smoothly. I haven't
ridden it yet as it's raining pretty hard.
I now have a set of stock igniters that I installed bullet connectors on the wiring. The igniters are bad but if anyone needs/wants them let me know.

SchoolDaGeek
Posts: 147
Joined: Fri Aug 26, 2011 8:36 pm

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby SchoolDaGeek » Mon Jan 23, 2012 11:22 pm

That is my point. People who were patient and would send their stuff away for testing?

I am still at odds with my own understanding how a 530 Ohm reluctor merits one diode with one 3.9K resistor biasing terminal G at startup to each module. This setup did not work for me the first and second times I tried it, but I did connect one side wrong due to the colored sleeves, and then banged my head up to buying a whole new setup, new coils again, and new modules again.

It would be nicer to hear back from those 4-5 people that Volker helped? With the TLC that Volker and Pinhead give to their bikes, it would make sense that these values are fixed. But with a multitude of conditions of no-start or hard-start, I was hoping that this MOD would cover various degrees of mistune, so that the other lacking areas could be addressed. It now seems that maybe 5-6 people in the world are running this 4 pin mod but are not present on the forum, on a CB650.

My earlier schematics was searching a trim pot resolution as a voltage divider that could be adapted to most any bike in various states of negligence.

But now, I may be interested in a cheap reversion to stock, even if the ignitor modules are "bad" because hard starts with full choke over 2-3 minutes are what it takes to get this particular CB650 running. I don't consider that type of ignition module bad.

I've been watching CAFERACER on Discovery channel weekdays between 1-5p.m. EST. Check your local listings.
Buy New, Wire Right. BNWR. LOL

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Volker_P
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Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby Volker_P » Tue Jan 24, 2012 2:15 am

SchoolDaGeek wrote:It would be nicer to hear back from those 4-5 people that Volker helped? With the TLC that Volker and Pinhead give to their bikes, it would make sense that these values are fixed.
As it seems it is forgotten: My ignition is still all stock, just running it like that since 20 years. Once long ago ignitors were molten and epoxied.
So sorry, no safe HEI configuration to be contributed from myself.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

Loudhvx
Posts: 37
Joined: Tue Aug 23, 2011 5:51 pm

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby Loudhvx » Tue Jan 24, 2012 11:19 pm

Loudhvx wrote:
One simple test you can do is to simply connect and disconnect 12v to the G terminal, briefly. If that action does not generate a spark, then there is a major, fundamental flaw somewhere. Not a minor one related to dwell, start-boost etc.


That is, with nothing connected to W. Nothing else connected to G. Just 12v to B, coil to C, and good ground to the heatsink.

If that doesn't create a spark, then the problem is not with the mod, it is with the igniter, or the spark coils, or your setup (i.e. incorrect wiring or bad battery).

SchoolDaGeek
Posts: 147
Joined: Fri Aug 26, 2011 8:36 pm

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby SchoolDaGeek » Wed Jan 25, 2012 2:08 am

Yeah I think that is the AutoZone test, or the multiple HEI Ignition module testers for sale on Ebay for 20 bux. As I said we are in the middle of winter so no work will be done for a while. I've gotten shocked and seen sparks with the plug wire connected to the spark plug laying on the head. I am pretty sure I need to thoroughly clean the reluctor system below the three screws and plate, and have that in hand before I suggest anything more.

I mean what is the resistance of sludge? ;)
Buy New, Wire Right. BNWR. LOL

jrjanes
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Joined: Thu Feb 02, 2012 12:30 pm

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby jrjanes » Thu Feb 02, 2012 12:35 pm

Hey i'm new to the forum, but I tried the upgrade with stock coils and I had a helluva strong spark resulting from it. Unfortunately as soon as I wired it up last night, my choke cable broke, so now it's back to mechancial.

klougnot
Posts: 149
Joined: Wed Jun 02, 2010 1:05 pm

Re: GM HEI: Cheap and Extremely Effective Ignition Upgrade

Postby klougnot » Thu Feb 16, 2012 11:15 am

Hi Pinhead,
What are your thoughts on using .7 OHM Accel coils with HEI setup? Accel says these coils are for CDI ignition, but I am thinking that since the primary resistance is the same as the C849 coils it should work. Am I correct, or am I asking for trouble here.

Details
ACCEL MOTORCYCLE 140404 - ACCEL Motorcycle Super Coil KIts large image
Ignition Coil Kit, Motorcycle, Yellow, 0.7 Ohms Resistance, CD Ignition, 4-Cylinder, Coils, Wires, Kit

Thanks!

-Kyle


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