1975 Evinrude 135 stator/charging issue.

gjmsd

Petty Officer 3rd Class
Joined
Oct 18, 2010
Messages
83
I'm finally finishing up my project boat and took it out for a test run. The motor doesn't seem to be charging. I look at the wiring diagrams, older forum threads and understand the fundamentals of the system, but when I started taking readings from the components, I get real strange data. Measuring the voltage across the stator when the engine is running seems to jump all over the place. My understanding is it should be around 16-20 VAC since there is no regulator listed in the wiring diagram. the voltage on my digital meter shows >130VAC and it jumps around. I thought this might be because there was no load on it (the rectifier was disconnected) so I connected up the rectifier and same thing. Measuring the voltage across the rectifier showed very high DC voltage in the range of the AC voltage I was seeing. Am I doing something wrong? None of these voltages seem correct.
 

jayyyy

Seaman
Joined
Jul 17, 2011
Messages
52
Re: 1975 Evinrude 135 stator/charging issue.

The rectifier is there to convert AC current from the stator to DC To charge the batteries. If the engine runs okay then the stator is supplying current to ignition and there is no need to test the AC side. To test the charging system connect a DC voltmeter or guage to the battery run engine at 2000 Rpm voltage should increase to around 13volts if working properly.
 

gjmsd

Petty Officer 3rd Class
Joined
Oct 18, 2010
Messages
83
Re: 1975 Evinrude 135 stator/charging issue.

There are several leads that come off the stator. The ones that run the engine (to the CDI) are different from the one ones that charge the battery. The voltages I get from either the AC or DC side seem to make no sense and they jump all over the place. At this point, I'm guessing I have bad coil(s) or broken/shorted leads. Preliminary check of the rectifier appears to be good, I may end up pulling it and connecting it to the AC side of my dirt bike (that I know is good) and see what kind of reading I get.
 

Haffiman

Commander
Joined
Dec 17, 2009
Messages
2,454
Re: 1975 Evinrude 135 stator/charging issue.

If charging is your only problem, concentrate on the two yellow leads out from the stator, the others are for ignition only. Ohm test, open to ground is ok, any reading they are shorted and stator must be changed.
Connect to the two yellow leads on the rectifier. The red from rectifier to B+ terminal on starter solenoid.
Hook up a battery and start the engine.
Charge should climb from 'resting' voltage 12,5 to around 14, depending on battery condition and rpm.
If no charge, measure AC from each of the yellow. If 'any' , most likely your rectifier is toast. If running without battery cables connected to the red from rectifier it will blow!!!!
You should have full flow from yellow to red on rectifier, blocked from red to yellow.
If you want the correct AC readings as per the manual, you need a DVA adapter to your multimeter to get the peak readings. Without it will not read correct even at AC setting.
 

gjmsd

Petty Officer 3rd Class
Joined
Oct 18, 2010
Messages
83
Re: 1975 Evinrude 135 stator/charging issue.

Haffiman, thanks for the info. Wasn't aware of the DVA but did some research and that is probably why I can't get a reading with any of my multimeters. Probably saved me a bit of work pulling the flywheel to check the stator. I'll be giving the rectifier a better look now. One question, should the rectifier work with the stator output from a dirt bike for testing or am I wasting my time? It seems the output from outboards may be different (quick spikes).
 

Haffiman

Commander
Joined
Dec 17, 2009
Messages
2,454
Re: 1975 Evinrude 135 stator/charging issue.

Not familiar with 'dirt bikes', but in principle any rectifier with a 2-phase input should work, if it holds the Amp!!! I believe most bike charging equipment has lower amp rating, unless you are carrying a 100Amp/hour battery on your dirt bike :rolleyes:
 
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