Motor just died

[99yam40]

Went back through the ignition system again. Everything looked the same as the first time through with the following exception. The first and second time through I measured the charging coil voltage unloaded at 290VDC, spec 200VDC. I never measure charging coil voltage loaded the first time. This time I did and measured 52VDC, spec 190VDC.

I also went through all the wiring for continuity and checked my grounds and all looked good.

Well now things seem to be pointing to the stator. Any other thoughts would be appreciated before I buy another spare part.

Thanks for the input!!!
Eastbayboy

I would wait for Rod to drop in again to see what he says.

I figured if it puts out OK unloaded but not loaded, there is a problem with what it is being hooked up to.
but that would mean the new CDI or the wiring.
maybe the charge coil can put out voltage but not enough current when loaded.
I do not know what is going on on this

[Eastbayboy]

Just wondering regarding the stator measurements.

Is a good unloaded measurement of the charging coil (290 VDC, spec 200), good resistance measurement ( 675 ohms, spec 660-710) and bad loaded measurement (52VDC, spec 190CVDC). Is this a common failure mode for a stator. I would have expected to see the loaded measurement and/or resistance also failing.

Any thoughts?

Eastbayboy

[99yam40]

you sure are confusing me with your numbers
one time you say 290VDC unloaded and the next 52VDC unloaded

[Eastbayboy]

99yam40: My error unloaded I measured 290VDC, loaded I measure 52 VDC loaded. I corrected the earlier post

[99yam40]

Hopefully Rodbolt can answer that question for you

[lastcast1962]

Same issue

I thought the kill switch was the problem too, after reading your post.

I know it won't start if the kill switch is out (and shuts down the motor if its running), but will it turn over the engine at the key switch after the kill switch harnessthing is pulled off?

I am having the same issue although my problem began just after putting new water pump on my 70hp , water flowing great , engine idled good then began to die slowly, once it quit I can no longer get it started and have lost spark to plugs , wiring all checks good . Where were you heading with your question ?

[lastcast1962]

I am having the same issue although my problem began just after putting new water pump on my 70hp , water flowing great , engine idled good then began to die slowly, once it quit I can no longer get it started and have lost spark to plugs , wiring all checks good . Where were you heading with your question ?

Looks like we are all covering this problem to the fullest but has anyone considered the key switch itself as the problem since the control circuit is con*****ed mainly by the key switch itself ?

[rodbolt17]

the only thing the keyswitch does is kill the engine.
you can check the stop circuit by unplugging the white wire at the CDI.
if spark returns test the stop circuits.
this ign system does NOT use 12v.

[Eastbayboy]

Lastcast1962, Rodbolt17: What I did to check the kill switch was disconnect the CDI connector and measure the resistance of the kill switch wire (white wire, pin 17) to ground at the CDI connector in the following states
1) cut off clip IN PLACE and ignition OFF, 0 OHMS
2) cut off clip IN PLACE and ignition to ON, OPEN
3) cut off clip IN PLACE and ignition to START, OPEN
4) cut off clip REMOVED and ignition to OFF, 0 OHMS
5) cut off clip REMOVED and ignition to ON, 0 OHMS
6) cut off clip REMOVED and ignition to START, 0 OHMS
All measurement were done with the throttle in neutral.
Also, I measure resistance from the CDI Kill Switch pin to all the other pins in the connector and they were OPEN.

Rodbolt17: I don't have the means to remove the kill switch wire pin from the CDI connector or know how to do it, so I have not done that.

[exeter27]

Any updates Eastbay? If you've found an answer, it can be really important in the future because you know someone else will eventually have the same issue! Thanks.

[Eastbayboy]

Even more baffled than before???

Well I bought another spare part it seems. I purchased a new Yamaha OEM stator, installed it and no change. I did go back and measure the Charging Coil resistance, loaded and unloaded voltages and they were pretty much the same as the old stator. The resistance and unloaded voltage was good and the loaded voltage was low (52 VDC, spec 190).

Not sure where to go from here other than a real mechanic. So I'm taking a break waiting for some subconscious inspiration.

No fishing in Florida this weekend.

Eastbayboy