Stator Rewrap

[km1125]

Thanks GA. I'll try to confirm this.

Yea, definitely check for decimal points. On my meter in the "20" scale, it will read up to 19.99 volts. On the "200" scale, it will read up to 199.9

 

[km1125]

Sounds like you have the HS coil figured out, but what did you do on the LS coil? Last I read, you were using a larger ga wire... did you convert the equivalent resistance for the length of wire so you would end up with (roughly) the same number of wraps?

And what about the direction of wrap? There was a question at one point about which way each coil was wrapped and how the two coils were interconnected. Both of these questions might impact whether the switch box acts correctly when it gets the signals from either the HS and LS coil. For example, if the coil was wound "clockwise" then the switch box (CDI) might see a positive voltage then the negative voltage. If it's wound "counterclockwise" then the switchbox (CDI) would see a negative voltage then a positive voltage. If it's designed for one, it won't work for the other.

 

[GA_Boater]

Sounds like you have the HS coil figured out, but what did you do on the LS coil? Last I read, you were using a larger ga wire... did you convert the equivalent resistance for the length of wire so you would end up with (roughly) the same number of wraps?

And what about the direction of wrap? There was a question at one point about which way each coil was wrapped and how the two coils were interconnected. Both of these questions might impact whether the switch box acts correctly when it gets the signals from either the HS and LS coil. For example, if the coil was wound "clockwise" then the switch box (CDI) might see a positive voltage then the negative voltage. If it's wound "counterclockwise" then the switchbox (CDI) would see a negative voltage then a positive voltage. If it's designed for one, it won't work for the other.

Since AC voltage has no polarity, it makes no difference if the switch box sees the negative or positive half cycle first because in half a cycle the sine wave will reverse.

 

[km1125]

Since AC voltage has no polarity, it makes no difference if the switch box sees the negative or positive half cycle first because in half a cycle the sine wave will reverse.

Not sure I agree with that, unless you know what is inside the "switch box". This is different than the alternator charging circuit because these two coils also dictate the ignition timing, right? This means that which phase comes first (positive going or negative going) would be important unless there's a full wave rectifier on the input side of the "switch box".

 

[Fed]

Pusher you should be working off Page 80 of the CDI troubleshooting guide.
As far as I know measuring voltages without a DVA type meter is futile.
Have you rewound the stator the same as it was when 'new'?
Where does this High Speed (HS) and Low Speed (LS) come from? Did you make it up?
What's with the 2 'extra' poles you wound?
Were these 2 poles being used originally, if so what for?

Do you know what stator you have?
Are your magnets glued or bolted in?
Strange the CDI resistance values differ from the OEM ones.

You wanted a project and now you've got one. :lol:

 

[GA_Boater]

It's toast and all the needed visuals were lost;



The way the coils are interconnected is what supplies the trigger pulses the switch box uses to calculate when to fire the plugs. I fear the interconnection wiring was lost.

 

[gm280]

I have to say the wire gauge on the original stator, even after being burnt, looks a heck of a lot larger then 42 or eve 32 gauge wire to me. But what would I know. I am only going from the picture GA_Boater provided above. Sure wish there could be some way to determine the original gauge and number of wines per coil are. JMHO

 

[km1125]

I have to say the wire gauge on the original stator, even after being burnt, looks a heck of a lot larger then 42 or eve 32 gauge wire to me. But what would I know. I am only going from the picture GA_Boater provided above. Sure wish there could be some way to determine the original gauge and number of wines per coil are. JMHO

Seems like a bit of clarification would help on several points. I don't know the specifics of THIS MOTOR, so someone please correct me if I say anything that is incorrect.

What I think you see in the picture are the alternator windings on the stator, which should indeed be larger than 42 or 32 GA wires. I believe there are three windings on this stator: the alternator, the HS coil and the LS coil. The HS and LS coils would be the 42 and/or 32 GA wires and each one is on a single pole of the stator. The other poles are all the alternator windings.

Pusher: I copied the pic below from the CDI manual that was linked to earlier in the thread.... can you confirm that the line I highlighted is the right one for your engine?

 

[Pusher]

It's toast and all the needed visuals were lost;



The way the coils are interconnected is what supplies the trigger pulses the switch box uses to calculate when to fire the plugs. I fear the interconnection wiring was lost.

Wow gentlemen! You guys got on it!!! The wraps seen above still connected are the alternator coils.

The Low Speed should be at the bottom of the picture still cooking off. It hadn't slid off the post yet. The high speed is the one that's roughly 40 AWG.
The low speed is about 34-36 AWG.

The extra poles were originally empty. I used larger alternator AWG wire so added the empty two posts to the circuit like theafter-market CDI product does.

I didn't make the LS & HS coil names up. I didn't want to post a picture from my manual in case it would break forum rules but there's an 60 or 70's model stator pictured there that shows the winding directions...... I'm ASSUMING nothing changed. But then we know what happens when we "assume" .

Magnets are bolted. I should have the A7 stator but actually have the A4 (or verse vica) so I assume the PO replaced it with an OEM already.


KM1125. Correct on all points.

GM, you suggested I not glue and try to make modifications after the initial test fit. Since I made up the winding jig, which works great btw, I can make removeable windings like the factory replacement parts. I think I over-emphasized the winding shortout problems so I back down from that. That said, I can reverse the coils CW or CCW.

The HS coil is right at the OHMs but the low speed I wrapped over-kill and had high OHMs. I don't know how that plays in since it's larger AWG.

Let me know if I can post the image from the manual and I'll load it up.

 

[Pusher]

Thanks everyone for the interest. I am way over my head in theory, math, science and experience.

I'm planning on bolting the evinrude on this winter so I can get the boat splashed in the spring but then I think I'm going to throw this Merc on a saw horse and keep at it if I get some more help from you guys.

If it looks promising, I'll write something up on the winding tool I pictured above. It knocks the socks off the bobbin.

 

[Pusher]

Are the $45 CDI switch boxes legit? Seems very affordable.

I'm not planning on buying one, but might build a wish list for next year.

 

[km1125]

Been a couple weeks since any updates... did you put it on the shelf for a while or still working on it?

 

[Pusher]

Put it on the shelf :-/
I'm not really sure how to test it, and if my switch box is bad then the plugs won't light up even if the coils are good. I might get back to it but it might end up in storage too. I definitely burned out on it... No pun intended.

 

[gm280]

Put it on the shelf :-/
I'm not really sure how to test it, and if my switch box is bad then the plugs won't light up even if the coils are good. I might get back to it but it might end up in storage too. I definitely burned out on it... No pun intended.

I can easily see how you are tired of it now. So put it away and down the road you can tackle it again if you want. I always told myself that I would rewind a stator if I get a bad one. But thus far I never had a stator go bad on any of my engines.

If you do take it back up, make sure you post it. I would be interested in seeing the final results. Have a wonderful Thanksgiving!