Electro mechanical problem no ignition on old engine

[tcmtech]

I would suggest just going to the local hardware store and buy a points ans condenser set for any small engine and just use the condenser from that.
That vast majority of magneto type ignition systems all use similar sized condensers and tend to not be all that fussy about slight mismatches.

I have a 1930's hit and miss engine with the condenser off of either a Tecumseh or B&S engine and it fires a nice hot spark despite being a 70+ year and brand mismatch.

As far as a DIY replacement I would suggest using 400 or 600 volt rated non polar mylar capacitors in the .47 - .68 uF range.

 

[Norator]

Putting a milliammeter in series with the grounded spark plug lead while slowly rotating the flywheel should give you a plus and minus needle swing. In principle.
Since >10 mA is perceptible as a nasty shock I'd expect this current to be >10 mA.

Even with no spark and the lead open-circuited you may hear a popping sound in a nearby AM radio.

 

[SimonTHK]

Simply loose the points and the condenser. I've used these modules: http://www.mytractorforum.com/showthread.php?t=115151 There are a number of varieties for different kinds of engines. I did a conversion a few years ago on a 35 YO mower and I've really been pleased.

ebay, wherever: **broken link removed**

http://www.amazon.com/Mega-Fire-Ignition-Module-UNIVERSAL/dp/B001OK9ZFG

Vibrator caps were rated to 1200 or 1600 V, such as these:

And then there is this guy selling these: http://www.jerry-howell.com/IgnitionModules.html

Go back to when I was 10 YO and hadn't heard of a capacitance meter and I had a VOM back then at 50K ohms/volt. If you find the cap shorted via a resistance measurement, it's BAD. If you test with an ohmmeter on a low scale and reverse the leads and get a "blip" then it might be good.

The caps are HIGH voltage. Think of it this way. if you had just the magnets and a coil, your generating electricity. the idea is to store this electricity in a capacitor. Now, when you OPEN the cap, the cap discharges into the coil.
So, it's kinda like generate, store and use as a pulse.

If I lose the points and condenser, how will I know that it is timed correctly?

 

[tcmtech]

If I lose the points and condenser, how will I know that it is timed correctly?

Because the magnets on the flywheel are timed to the magneto coils same spot the points open and close at.

 

[SimonTHK]

Because the magnets on the flywheel are timed to the magneto coils same spot the points open and close at.

Ok, I thought maybe the capacitor was there to even something out there.... anywho might try such setup

 

[KeepItSimpleStupid]

In reality, Electronic and points ignition use a slightly different ignition timing, but the circuit compensates for this. Early Tecumseh engines had an insert to place in the flywheel for electronic or points.

The other timing marks are physical within the engine.

A lawn mower runs on fixed timing. In the "deep details" timing is slightly different for electronic ignition.

You don't have to actually remove the points when you install the electronic ignition module. I didn't. I mounted the gizmo under the flywheel housing.

In my case, I also added an external push to stop switch because the universal cable I used won't traverse from full choke to off.

 

[SimonTHK]

Ok one major issue. I can constantly measure ground on the shutoff wire. I cant imagine anything but that it is wrong. Though I cannot find any failures in any wire. Can anyone confirm my suspecien?

 

[KeepItSimpleStupid]

On page 50, here: https://www.google.com/url?sa=t&rct...Q8QUncHSgDyxgUHRA&sig2=oaZSMtGzE4ibdiu0cTyswQ

there is a pic of the ignition system.

The points, condensor, coil and the kill switch all go to the same point and each of those components go to ground.

So, with the points open, you will see low resistances on each side of the kill switch because of the low primary resistance.

To check what's going on, disconnect the coil wire from the points.

Now check that the points make and break contact and the kill switch makes and breaks contact and check the condensor for shorts.