Onto a new learning curve…CD ignition

[johnyrude200]

Hi guys,

I’ve started up the hill to learn more about CD ignition. I understand the basics; charge coil, ignition sensor, out to the powerpack, and then out to the two coils. My issue is that I feel much like I did when first learning about how to fix magnetos about a year ago. I have been reduced to trial and error because I don’t think I have the right testing equipment.

Going by the service manuals, they call for a continuity meter, neon light tester, voltmeter, and spark tester. I am not an electrician, so some of the terminology is still new/unfamiliar to me.

I have both a digital and analog multimeter and a spark tester. I have gotten along far enough to test the charge coil and ignition sensor for resistance and shorts using the analog meter (manual explains how). My issue is figuring out how to test the regular coils and powerpack. I do own a merctronic, but the newer coils, of course, don’t have a range to them I am aware of (unless these are specified in more recent service manuals).

I think I’ve just gotten lucky so far (just starting to move into the 80’s/90’s/00’s motors). In most cases, it’s been a simple powerpack swap, coil swap, or faulty wiring/bad ground in any of these components.

I’m stumped because I have a motor where I installed a new powerpack (or I believe it is…it was NOS), made sure all connections were good with good grounds, and during initial cranking got weak/intermittent spark (more on one lead than the other) and now there is no spark on either. My beef is that I don’t know how to trace the problem back to the source and identify it.

Is a digital multimeter adequate for testing and identifying issues in a CD ignition? I’m unfamiliar with digital multimeters; the service manual calls for ‘setting the meter to negative and 500’ when doing a powerpack test. That’s where I’m stuck – how to set the multimeter correctly.

Thanks again.

[frankr]

In the first place, the old manuals are obsolete. The neon tester is history. Nowadays, you need a DVA meter, or adapter for your present meteer. Otherwise known as a peak reading voltmeter. The pulses come and go so fast that a regular meter cannot respond and read them accurately. Complete testing instructions are on the CDI website

[dan-in-tn]

Thats the standard answer I gave you JohnnyRude. You could get a Stevens CD-77, but I would go with the Fluke DVA Frank is talking about. In the long run there is too many other things you can do with that meter. CDI is the place to check on it and their manuals are best for learning how to use it to its potential. I will see if I have another of their manuals around here somewhere.

Dan in TN

[johnyrude200]

You guys have got me excited now. I am totally ‘dumb’ when it comes to seeing how valuable these tools are for various applications. Doing a little homework, I found these links:

http://www.ebay.com/itm/CDI-Outboard-Fl … 541b952cf4

and

http://www.stevensinstrument.com/peak_dva.htm

The stevens adapter is only $57.00…I’m guessing either will do the same thing? My only issue is now learning how to understand what I’m doing with a DMM. Yes, I am that new to this stuff (but I learn quick with a little help).

My other question is when I go to the CDI website, I am only finding a DVA chart to download which goes into stator and trigger test specs. Would I still refer back to the old service manuals for component specifications while conducting the tests (I’m guessing yes).

[jerry-ahrens]

One thing you can do when using CDI Electronics parts is download the PDF instructions for the particular ignition part you are testing. For example if you are working on a 1989 150 hp OMC outboard and want to test the powerpack, simply look up the correct replacement powerpack for that engine. Once you know the part number, you can click on the PDF file for that particular part for full troubleshooting instructions. As far as a test meter, I prefer an analog peak reading volt meter. I own and use a ES [electro specialties] analog meter. The Stevens meter shown in your link is also an excellent choice, along with the anphenol plug test adapters if working on OMC engines. CDI Electronics also publishes an ignition systems troubleshooting guide that list specs and detailed troubleshooting instructions for many outboards. A must have in the shop. I use mine frequently.

[frankr]

quote johnyrude200:

You guys have got me excited now. I am totally ‘dumb’ when it comes to seeing how valuable these tools are for various applications. Doing a little homework, I found these links:

http://www.ebay.com/itm/CDI-Outboard-Fl … 541b952cf4

and

http://www.stevensinstrument.com/peak_dva.htm

The stevens adapter is only $57.00…I’m guessing either will do the same thing? My only issue is now learning how to understand what I’m doing with a DMM. Yes, I am that new to this stuff (but I learn quick with a little help).

My other question is when I go to the CDI website, I am only finding a DVA chart to download which goes into stator and trigger test specs. Would I still refer back to the old service manuals for component specifications while conducting the tests (I’m guessing yes).

Go here to learn what it is all about:
http://issuu.com/cdielectronics/docs/tr … 61/2010855

As for what to buy, the Stevens adapter, or similar, is all you need if you already have a multimeter. Of course if you were seriously into doing this stuff as a profession, buy the DVA Tester.

Gotta tell you though, you could actually cobble up your own DVA Adapter. I did. Very crude though, but it shows how little is actually in the real deal.

But read through and try to understand what the tests are and what they are about. If you understand the ignition system, you really don’t need testers to fix one in most cases, though they are invaluable in the puzzler that you can’t figure out. Usually, good ol’ common sense will diagnose it.

[frankr]

Following up on what I just wrote, as you read through the instructions I just posted, you will quickly realize there are CD Ignitions, and there are CD Ignitions. The earlier OMC systems were powered by 12V from the battery. State of the art at the time, but junk by today’s standards. And the most troublesome, both in reliability and ease of diagnosing. OMC then came out with "Mag CD" on some models in 1972 and more in 1973-up. Mag CD generates it’s own operating voltage, and is light years better then the battery system. And what I had in mind when I said you can diagnose them with common sense. All of the small motors will have some sort of Mag CD, even your lawn mower and chainsaw.

[johnyrude200]

I feel like an idiot asking this question but I guess we all have to start somewhere. I am guessing the ‘alternator driven ignitions’ are the ones I should be reading up on (page 39)? All I’m interested in doing right now is learning how to troubleshoot your typical small HP OMC (up to 40hp) which uses CD ignition. I’m guessing it says alternator driven, but also is the same procedure for motors without an alternator.

I have no issue buying the appropriate testing equipment as necessary – that’s what uncle Sam refers to as a "business write off."

Thanks Frank.

[fleetwin]

Well, once again, what seems like simple terms can cause a lot of confusion. None of the OMC magCD systems (excluding FFI/ETEC) were "alternator driven". There are separate windings for the alternator that had nothing to do with the ignition system. Adding more confusion, the ignition windings are referred to as "charge coil(s)". The only thing the two systems have in common are the flywheel magnets.
Most of the magCD systems you are interested in working on are actually pretty simple, so it is best to KISS. Sometimes, our test equipment can cause a lot of confusion along with incorrect conclusions as well. There are so many different settings and voltage ranges used, it is very easy to get derailed by a meter that is set/calibrated improperly. And, now that there are adapters that can be used with fluke meters, I’m sure confusion will increase. Remember, there is nothing more valuable than common sense. In other words, coming up with a conclusion that there is no charge coil output on a 25hp (CD2) that has spark on just one cylinder just doesn’t make sense!
There are basic tests that should be used on the CD2 system before diving into output readings. The first simple test is the stop switch elimination test. The stop circuits on these engines can cause many ignition problems, especially on salt water engines. The next simple test is checking those amphenol (rubber plugs) connections. The pins and sockets sometimes get pushed back into the rubber plugs, or bent/corroded causing weak/no connections, and salt water surely can aggravate these conditions. Investing in the three amphenol pin/socket tools is a must. Never cut the wires to avoid dealing with the pins/sockets, butt connectors/black tape is a NO NO. Next, always be sure to check coil and pack grounds with an ohm meter calibrated to the low ohms scale. Again, using a meter you are unfamiliar with, or calibrated to the wrong scale, might allow you to overlook this simple problem.
Finally, yes I realize that the powerpack is the most complex component, and is usually the cause of the problem. BUT, it is important to check all components when replacing the pack. Yes, the new pack might solve your problem for now, but the new pack might be damaged quickly by the bad connection/weak ground/marginal component you didn’t check.

[johnyrude200]

Thanks Fleetwin, I’ve gotten to the point where if there is no spark, missing 1 spark on a coil, or weak spark, I go through the stop test, check all connections and grounds.

What I am in need of is the ability to test each individual component to identify a faulty part of the chain. Last year I picked up a merctronic model 98 for the old magnetos and have never looked back. That instantly made everything 100x easier because it eliminated trial and error and endless hours of swapping out components trying to identify a bad component.

I need to be able to do the same with the CD ignitions in the interest of time and productivity. The fact that it took me 5 hours yesterday using trial and error on one of these CD ignitions tells me I don’t have the tools or knowledge to do this job quickly, effectively, and consistently. Hence, turning to all of the veteran’s advice on how to up my skills. I want to understand well what I am looking at and why it isn’t working; I understand the basic theory of operation but need more of the ‘why’s, what’s, and how’s’ of issue diagnosis for repair work.

School of hard knocks as Frank said back on the old boards.

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