NEGATIVE voltage off stator?!? 1979 70hp 3 cyl 2 stroke

dorsett59

Seaman Apprentice
Joined
Jun 4, 2008
Messages
49
Hey, all
I've been chasing down this problem for a while now. Out of ideas.
Engine runs fine. Produces good power up to 3000 rpm. Then, nothing. Used to pull strong up to 5200 last year.
Checked fuel, air, timing. All good.
Checked the voltages and resistances off the stator. All worked fine on the low side. The resistance values were fine on the high side. But, voltage readings on the high side were weird. On the analog multimeter, needle, looked negative.
So, according to the CDI electronic troubleshooting guide, I replaced the stator. No change. Stuck a digital multimeter on it, and I'm getting NEGATIVE voltage through the stator. And that's using two rectifiers that both check out good.

I'm out of ideas.
Anyone else have this problem? New stator, new rectifier, negative voltage on the high circuit.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,633
Re: NEGATIVE voltage off stator?!? 1979 70hp 3 cyl 2 stroke

bad pack......
 

dorsett59

Seaman Apprentice
Joined
Jun 4, 2008
Messages
49
Re: NEGATIVE voltage off stator?!? 1979 70hp 3 cyl 2 stroke

Bad pack.
Is that the switchbox? Coils? Something else?
 

Jlawsen

Master Chief Petty Officer
Joined
Apr 22, 2012
Messages
810
Re: NEGATIVE voltage off stator?!? 1979 70hp 3 cyl 2 stroke

Bad pack.
Is that the switchbox? Coils? Something else?

I'm a little confused. I agree with the bad switch box diagnosis. If your testing output at the rectifier then your testing the charging coils and they have nothing to do with the ignition. The output from any of the stator coil outputs is A/C. Make sure your meter is set to A/C voltage. Before you throw any more parts at it, go back to the CDI website and order their spark gap tester. Using that tool you'll be able to see what's wrong just by how far the spark will jump and the color. Sounds to me like you're dropping a cylinder.
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: NEGATIVE voltage off stator?!? 1979 70hp 3 cyl 2 stroke

You need a DVA to get accurate readings from the stator.
 
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