Stator/CDI alternative test

[Vandkanten]

I have an Evinrude 3cyl 35 HP 1998 outboard with no spark.

I have read and seen alot of different test of how to test the stator and in generel test and diagnose your outboard.
Well, it isnt that difficult. But everything gets alot easier if you had spareparts to test with.

Right now I am going to order a new stator for my outboard, but at the same time I thought of a new way to test if my old stator is bad.
Well I have done the ohm and output tests already. I also have tested all other parts.
In my case I am still unsure if it is my stator.

Anyway, my stator test goes like this:

Disconnect the stator totally. And connect from power supply 12V dc and 220V AC to the CDI controller (replacing the stator function). Now cranck and see if you got spark.
If you got spark the stator is bad.

What are your thoughts on this? Can it ie done?

 

[jakedaawg]

opcorn::bolt:

 

[RCO]

Your "test" doesn't make sense from an engineering standpoint. I don't think you are understanding how the system works. If you really want to diagnose electronic ignition systems, invest in a lab scope and learn how to use it . Replacing parts until you find the one that fixes it is expensive and time consuming .

 

[Vandkanten]

Well, the coils in the stator is 3 power sources, generating power when the magnets in the flywheel rotates.
one power source for the refitifer/battery Charger. One for low volts for electronics like CDI and the timing sensors. And one for high volts for creating the sparks through a super highvolt coil timed by the CDI/timing sensors.

​​​​​​So the stator is nothing else than a variable power source, it creates more power at high rpm.

Correct me if I am wrong.

Sometimes you can have a part failing strangely and your multimeter tells you that the part is okey.
A multimeter operates at low voltages and doesnt always tell the truth when it comes to coils. Thats my experience.

I have created my post here to disguss if it is possible to replace the stator with two power supplies creating power within range of the stator.

I cant see why it shouldnt work.
​​​​​​

 

[Vic.S]

Well, the coils in the stator is 3 power sources, generating power when the magnets in the flywheel rotates.
one power source for the refitifer/battery Charger. One for low volts for electronics like CDI and the timing sensors. And one for high volts for creating the sparks through a super highvolt coil timed by the CDI/timing sensors.

​​​​​​So the stator is nothing else than a variable power source, it creates more power at high rpm.

Correct me if I am wrong.

Sometimes you can have a part failing strangely and your multimeter tells you that the part is okey.
A multimeter operates at low voltages and doesnt always tell the truth when it comes to coils. Thats my experience.

I have created my post here to disguss if it is possible to replace the stator with two power supplies creating power within range of the stator.

I cant see why it shouldnt work.
​​​​​​

You might find the CDI troubleshooting guide helpful

http://www.cdielectronics.com/troubleshootingguide/

 

[Vandkanten]

Thank you Vic. I am aware and are using the CDI troubleshooting guide when needed Can't live without it.

But my post is more about creating a discussion about if it is possible to replace the stator with a two power supply source, only for a testing scenario ofcouse.

This is meant as an alternative way to test if your stator is bad.

What are your thought ?

 

[racerone]

What 220 AC power supply are you thinking of using ?-----How would you limit amperage to keep the CDI controller from melting into a puddle ?

 

[jakedaawg]

K, I'll bite,...

where did you come up with 220v ac? I seem to think it's a variable ac voltage produced by the stator.

also, how many phases?

 

[Vandkanten]

The stator has 2 power sources that is needed for running the engine.
Power source 1: Brown/BrownYellow: 150-400V AC
Power source 2: Orange/Black: 11-22 V AC

I would have two variable labratory power supplies connected, one running 12 V AC and one running 200 V AC.
My stator is an 3/6 amp, so it is no problem for my power supplies to deliver the same.

I dont think that the CDI box will melt here is why

A part of the CDI is a capasitor (small battery) that gets filled with enery and holds it. When the timing is right the CDI fires that enegy at the coils and the voltage will alway be the peak voltage of the stator/power source.
Low RPM=150 V AC, High RPM = closer to 400V AC

So the coils primary side gets somewhere between 150-400C AC. Let say that the coils is 1:100, so the secondary side will fire 20.000 V at 200 V primary side.

A spark plug fires at 12000v to 25000v, sometimes even more.

Of what I have heard, you will have a very low current when you have high voltage and vice versa.

Because the current is always calculated by voltage / resistance, so even if the stator/power supplies can deliver 6 amp, it is not an guarantee that it all will be used. 6 amp is just the limit of the power source/stator.

So if you want to melt the CDI into a puddle, you have to rise the voltage.

Please correct me if I am mistaken.

After thinking, calulating and writing all this I am even more confident in that you actually can replace the stator using this alternative way to exclude/conclude that your stator is bad.

If I am right in my theory, then it will be very easy to tell if your stator is bad. Crossing my fingers.

What I need is someone telling me that it cannot be done and explains to me why.

 

[F_R]

I am not going to tell you that it can or cannot be done. I haven't tried it and I doubt anybody else has. You are in uncharted territory. You seem to know your stuff though.

But just a couple of comments for you to ponder on. About the AC Amps: That AC voltage is rectified before being fed to the capacitor. The capacitor stores it as a DC voltage. So we have to consider the current rating of the diodes in that rectifier. I do not know how much current the charge coil is capable of generating. If necessary, the current in your proposed setup could be reduced by a resistor in series with the supply. As you know, the capacitor would still rise to the peak supply voltage, over time. I have no clue whether this is an important argument or not. But ponder on it.

BTW, I admit I am not familiar with that particular motor. But the ones I am very acquainted with do not have a 12VDC input. You may be right, I don't know. Or are you thinking of the trigger circuit?

 

[daselbee]

The 3/6 amp spec you refer to is the charging capacity for the battery charge coils of the stator.
Look at the size of the wire in the ignition charge coil itself...not the lead in wires. Very small gauge.
Tells me very very low current supply capacity of that coil.

Now look at the wire size of the battery charging coils. Compare.

I agree with racerone. That powerpack will melt.

 

[stewtn]

This is a great step by step test page for both Stator and R/R. Its for a motorcycle but applies exactly the same.

 

[Vandkanten]

Another one thinking that the CDI will melt.

Let say for a moment that the CDI is just a light bulb. A restistance.

an electric light bulb has a wirein it that at the given rated voltage will carry a current just large enough for the wire to get very hot (giving off light and heat), but not hot enough for it to melt. The amount of current in a circuit depends on the voltage supplied: if the voltage is too high, then the wire may melt and the light bulb would have "burned out real time". Similarly other electrical devices may stop working, or may even burst into flames if an overvoltage is delivered to the circuit.

It is when you apply overvoltage that you can destroyer and melts things.

So as long I keep my voltage within range (150-400 V AC) nothing will melt.

 

[Vandkanten]

F_R thank you for clarifying thay the output og the CDI is DC. I totally have overseen that a capasitor only stores DC.

About the low voltage stator output (AC), one goes for the battery/retififer. And the other goes to the CDI.
I Guess that the lowvoltage AC is being retified too, generating lowvoltage DC for the CDI electronics and for the timing sensor at the flywheel.


When I am ready and have collected all relevant information I will setup a test scenario for this.
Because if I am right, you can test if your stator is bad in minutes.

 

[justatech1]

Did anyone ever follow through with this? Im also tinkering with this and a pico 4425 lab scope.

 

[Crosbyman]

best not to revive old posts .... post is 6 years old so it it fixed or sold !

as to the stator it is just wire coils energized by the FW so coils can be bad in few ways ...
open... grounded shorted out of specs all of which will produce no or low ac volts at a given RPM measured with a VOM/DVA .