Onan genset 4.0 no spark. Help

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PigCreations

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Thanks DonTom for the reply. When it was tested, the gen was out of the RV and had no load on it. Finally had the chance to look at it today. Didnt start it but noticed a thick oil residue on the copper bindings. Could this be causing the wires on the stator to be getting too hot?
 

DonTom

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. Didnt start it but noticed a thick oil residue on the copper bindings. Could this be causing the wires on the stator to be getting too hot?
Can you take a photo of it and post it here?

But what I am thinking is that you have shorted out stator windings. Sometimes we can tell just by looking.

For an example, here is a stator I removed last April from my 1984 Venture motorcycle shown on the right. Would not charge at all. The used good replacement is on the left.

One look and I had no need to even test the stator on the right. Bike now charges like new with the stator sown on the left. Should be good for another 37 years, unlike me, unless I make it until I am 109 years old.

-Don- Reno, NV
Stator.JPG
 

DonTom

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Here is a couple pics of the stator. The windings look a little dark but not as "burnt" as your stator.
Yes, I agree, nothing obvious there by looking. If you have the specs of the resistance on the coil and an ohmmeter that can check very low resistance, it's one way to be more sure. Probably a fraction of an ohm is normal for the windings and also make sure no shorts to ground from the coil.

-Don- Reno, NV
 

PigCreations

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Riverdale California
sorry for the delay, losing motivation as I am frustrated with this thing. I have it back in the motorhome, it will not turn over, nothing happens when I try to start it. Did notice the resistor on the stator (#14 in the attached pic) gets super hot has soon as I connect the battery. Wondering if the rectifier/diode (#33 in second attached pic) could be the problem. Is that rectifier/diode directional or is it just bad?
 

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DonTom

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Is that rectifier/diode directional or is it just bad?
Diodes will switch off with the opposite polarity of what turns them on. But your voltmeter has to have enough voltage to turn it on and if it's a high voltage diode it may not turn on from the low battery voltage in the ohmmeter. A normal silicon diode drops 0.7VDC, but high voltage diodes are made from many diodes in series in the same package, so of there are ten diodes in series internally, then it needs at least seven volts to read that one HV diode package.

That resistor looks like a high wattage wire round resistor. It will get quite hot in normal operation. Too hot to touch will be the norm there.

-Don- Reno, NV
 
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