Ignition tests (large post)

Tue Jul 17, 2012 4:26 pm

Well here goes my attempt at testing procedures. As no one volunteered to proof my work to see if I’m right in my way of doing things don’t assume I’m correct. If I have something wrong or I should add a test let me know. As per brichters request I tried to keep it simple.

These tests shown here are for a no spark scenario with a distributor ignition. I assume that if you know you have no spark that you do have battery voltage. These tests should work on almost any similar engines, including single cylinder. The sequence may differ slightly and some may not be needed depending on how the unit is wired.

The mock up in the photos are, I believe, the way the Cub is wired from what I see on my Cub and what's in the operators manual. It is set up as a 6 volt positive ground. As you can see I used a single spark plug instead of a distributor cap to keep the mock up small. Also you may notice that my volt readings may be a little low, that’s because I’m using a battery that is no good and with it being bad the charger doesn’t put out much voltage.

The Pos. of the meter or one side of a test light goes to the Pos. (+) post of the battery or to a good ground, for all the tests shown here. For all of these tests a volt - ohm meter or a test light will work. I have both hooked together in these photos. Make sure you always have a good connection with the meter or the test light.

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Diagnosis:
Test 1; No light or voltage; Wire between starter and AMP gauge bad or poor connection.
Test 2; No light or voltage; Amp gauge bad.
Test 3; No light or voltage; Wire between gauge and regulator bad or poor connection.
Test 4; No light or voltage; Regulator bad.
Test 5; No light or voltage; Wire between regulator and switch bad or poor connection.
Test 6; No light or voltage; Ignition switch bad.
Test 7; No light or voltage; Wire between coil and Ign. switch bad or poor connection.
Test 8; No light or voltage; Coil or condenser bad. (possibly points shorted also)
Test 9; No light or low voltage; Normal condition. If you have light or normal voltage, wire between coil and distributor bad or poor connection.
Test 10; No light or voltage; Wire between coil and distributor bad or poor connection. (you should already know this from Test 9) or condenser bad. (disconnect condenser from points, if you get light or voltage then condenser is bad)

If after the tests you can’t find the problem, then the condenser or the coil is bad. I believe how to check these may be in the “HOW TO FORUM”

Edit:
Also remember, each Test diagnosis is based on having passed the previous test.
I also edited Test 9 diagnosis to add low and normal voltage.
Last edited by birddog on Sun Jul 22, 2012 7:33 pm, edited 1 time in total.

Re: Ignition tests (large post)

Tue Jul 17, 2012 5:59 pm

That is great, Mark. I and the other electro-dummies really appreciate this.

Re: Ignition tests (large post)

Tue Jul 17, 2012 6:05 pm

Nice. Thanks for your efforts.

Now if I can talk Billy Ray into taking me up there and Thanking you in person while we enjoy your collection of toys! :mrgreen:

Re: Ignition tests (large post)

Tue Jul 17, 2012 7:17 pm

Mark:

I would have volunteered but since I am electrically challenged so would have been of minimal help. I agree with Billy Ray's comment - thanks from those of us who are electro-dummies :D

I gonna reread this a lot I think :!:

Re: Ignition tests (large post)

Wed Jul 18, 2012 11:31 am

Well, a lot of work went into that setup and will be helpful to many folks!

I like schematic diagrams but I know many or most folks like photos and pictures to help with the tracings. These should be useful. One thing you can see is the cub wiring seems daunting at first but all the major components easily fit onto a relatively small board. Those components are just spread out on a cub. Much less intimidating if thought of as stuff on a small board rather than stuff spread out over a large area on a cub.

Re: Ignition tests (large post)

Wed Jul 18, 2012 12:44 pm

Thanks for the kind words. It probably would have been a lot less work if I had remembered the AMP gauge when I did all the work the first time. I was about 3/4ths of the way done with all the editing when the light bulb went on in my head that with out the AMP gauge I also had the wiring wrong. I guess it's just to hard to try to tell where the wires go while looking behind the dash of the Cub, especially when they're all painted red. So I dug out my operators manual (thanks again Eugene) and looked at the Cub closer so as to get it right. Then to add insult to injury after editing the next batch of pictures I noticed they were all blurry so I had to retake them a third time.

Landreo, I may put something together in a schematic version also. That's how I originally planned to do it until I came up with the way I did it. I probably have 2 - 3 hours work in the schematics already.

I'm also working on a mock up/ test stand to do something similar with the charging system.

Re: Ignition tests (large post)

Wed Jul 18, 2012 1:32 pm

Thanks for all your time and effort. I hope this gets into the "how to" section, so it remains easy to find. Ed

Re: Ignition tests (large post)

Wed Jul 18, 2012 3:23 pm

Very nice work. i like the way you have it setup.

Re: Ignition tests (large post)

Fri Jul 20, 2012 7:48 pm

Mark:

The article is really good. Looks like there really isn't any major problems with it so I guess Bill will copy it to the How To Forum. I do know that it is definitely going into the CBoK. Looking forward to the schematic to include with this one and of course your next project. I am beginning to get this and that is something.

Re: Ignition tests (large post)

Fri Jul 20, 2012 8:28 pm

Landreo wrote:I like schematic diagrams.
Me to. I find schematics much easier to understand what each appliance is suppose to do and and how they function.
birddog wrote:Landreo, I may put something together in a schematic version also. That's how I originally planned to do it until I came up with the way I did it. I probably have 2 - 3 hours work in the schematics already.
My one suggestion on schematics is to present one system at a time, eg. Ignition system. Then another schematic on lighting, then starting, etc..