1969 Evinrude 55hp Stator Test

I performed a stator test as follows:

1. Disconnected positive battery cable
2. Disconnected stator leads
3. Connected an ohmmeter between the (yellow) wires

The meter read infinity. The manual stated I should get a reading of 0.75 ohms +/- 0.2ohms (9 amp system). The windings are therefore open and I should replace the stator. I'll order one today as long as someone can verify these results (Hightrim, Tashasdaddy, F_R, Joe Reeves you guys have been right evey time I have asked questions before). I don't understand why the last time I ran the boat the rectifier felt hot. I tested the voltage at the battery with the engine running and after I turned it off and there was no difference (12.3 volts both times).

Thanks guys iboats forums rock!

GB

Re: 1969 Evinrude 55hp Stator Test

I think before all else Tao I would go over all my connections with a file, emory cloth, what have you, and make them all shine, then re tighten them all down. Check the wiring for crunching as you flex it, or look for buldges in the insulation, sure signs of inner corrosion.

Connect the red meter lead to either yellow lead and meter black lead to ground to check for shorts. An infinite reading on HI ohms scale indicates the windings are good. Connect the ohmmeter on LO ohms scale between the yellow wires. A reading of .75 ohms + or - .2 indicates the windings are good, and an infinite reading indicates the windings are open. If windings are found to have failed, the stator must be replaced. Did you check for a short first.

Re: 1969 Evinrude 55hp Stator Test

I did check the stator for a short and it was not indicated i.e. ohmmeter set to high and 1 displayed when red lead on either yellow and black to ground (I assume 1 is the highest resistance indicated and therefore there is no short in the stator and I tried multiple ground points).

I did not start the thread with the correct information either. When I tested resistance between the yellow wires (meter set to low scale) the reading was 0.000, so it isn't indicating the windings are open but there also isn't any resistance (I triple checked the meter setting, contacts, and correct application).

GB

Re: 1969 Evinrude 55hp Stator Test

Have you tested the rectifier as per you manual?

When voltage enters the rectifier in the wrong direction it will instantly burn the diodes that make it work. If the heat melts the potting in the rectifier, the wiring can fuse with other wires causing smoke and in bad circumstances fire. That is when it is possible for the 12.65 volts from the battery to flow through the rectifier and destroy the components of the ignition system.

Probable causes that may damage the rectifier are as follows.

a. Battery cables loose or reversed;

b: Battery cables disconnected while engine is running;

c: Faulty ignition or battery switch;

d: Voltage applied while testing engine components;

e: Bad or weak battery and/or battery cables.

Re: 1969 Evinrude 55hp Stator Test

I tested the rectifier as the manual suggests even though I replaced it 3 months ago. It is good.

What do you think about the stator showing no resistance at all?

GB

Re: 1969 Evinrude 55hp Stator Test

Will your meter indicate a resistance of less than an ohm? Many will not, especially the cheaper analog ones. In that case, you would be seeing the 0.00 ohms instead of the 0.75 ohms, and I would consider it normal, a meter problem, not a stator problem.

If you do have a quality meter capable of reading less than an ohm, the 0.00 would indicate shorted windings, which is unusual. In that case it would also probably show physical damage or be discolored from heat.

Infinity would indicate open windings, junk.

Re: 1969 Evinrude 55hp Stator Test

FR I was just about to ask what type of meter he had. Do you think his windings could be shorted, just not quite yet showing signs of heat discoloration? He did mention his rectifier was heating up. If so, Tao I would go over the possible causes of rectifier heating as listed above.

Re: 1969 Evinrude 55hp Stator Test

On those style stators...... 0.75 ohm (3/4 of an ohm) would register on most ohm meters as a dead short. No ohm reading between either yellow lead and ground proves that the stator windings are not grounded. If these readings are what you're encountering, consider the stator to be okay.

The rectifier...... Test it as follows, then let us know what you've found.

(Small Rectifier Test)
(J. Reeves)

Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.

Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.

Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.

Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.

When time permits, visit my store (copy/paste) at: stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store

Re: 1969 Evinrude 55hp Stator Test

Good question about the multimeter. Mine isn't too expensive (digital) but here are the resistance scale settings:

20M
2M
200K
20K
2K/arrow with cross
200/amplifier symbol

I tried testing the stator on all of the above settings and never got a reading other than zero. I tested the rectifier and it appeared to test good.

GB

Re: 1969 Evinrude 55hp Stator Test

I've never used a digital meter, always an an analog (needle type) meter. I'm unsure if a "zero" reading on a digital would be the same as no needle analog movement or vice versa. Frankly I prefer the needle reading over the digital.

Re: 1969 Evinrude 55hp Stator Test

Go to Radio Shack and buy a 1-ohm (or less) carbon resistor and test it with your meter and see what it reads. Keep in mind the tolerance spec of the resistor, 10% is common, 5% almost as common.

At least then you will know how your meter performs.

Re: 1969 Evinrude 55hp Stator Test

My multimeter can test to the 10th of an ohm. I have attached two pictures that show the meter, resistor, and setting used to obtain the reading.

This information was very useful because I finally set the meter correctly for the stator test. The result??? The stator is good. At least it tested within the tolerance specified in the manual (My meter read .9ohms on the 200 scale where the 10 ohm resistor read 10.2).

This has been an exhausting process of elimination to say the least. My motor wont idle under load and runs rough at low idle settings. I have written posts about this before. I have rebuilt the carbs, tried multiple float settings (I am back to the correct setting for the floats by the way), replaced fuel lines, adjusted the needle valves, cleaned the points, adjusted the points (none of them are over .010), checked wiring, replaced the plugs and wires, etc.

I am ready to replace the distributor and rotor. Believe me I am not just throwing money at the problem, each fix I have done needed to be done.

GB

Re: 1969 Evinrude 55hp Stator Test

Firstly, you're looking at a 40-year-old engine that was finicky at idle to begin with. If the prop had a ding in it, the vibration would etch the low speed needle and wallow the low speed needle receptacle, causing it to run rich as fuel flowed by where it should have leaned out. (That was one reason they went to fixed low speed jets). You might try a set of fixed-jet carbs. I haven't seen that you balanced the carb linkage, though if you're this deep into electronics, you probably thought of the linkage long ago. As far as the rectifier, it's SUPPOSED to be hot, if it's doing its job. Look at Yamaha covers for their regulator/rectifiers: they're scared of suits, so like McDonalds' coffee, they fel a need to warn folks it's hot. Forty years ago people had harder hands and no curiosity about touchng engine parts, so the fact that the rectifier is warm was a moot point. If your battery goes dead quickly, or the tach doesn't work, suspect the rectifier. If the engine after replacing the points runs on only one or cylinders, then give consideration to the stator. At this point, I think you're chasing ghosts with your testing.

Re: 1969 Evinrude 55hp Stator Test

Ah, points.

Verify your point contact quality then recheck gap setting AT EACH LOBE.

These ignitions are critical of point quality as well as gap.

Also check the point lead wires for ANY chaffing throughout their travel as timing is advanced.

Ensure compression is uniform.

As previously stated get back into your carbs.

Many people forget that points have been arouund far longer than many of the meters that we use.

Your stator issue, it is probably OK, but long before I rely on ANY meter I use the old method of a 12 volt battery and a test light in series with the stator, I proven stators bad when a meter say good and the ignition still would not fire.

NOTE: DO NOT USE THIS METHOD WITH TRIGGER COILS, you will melt them using anothing greater than a flashlight battery.

Re: 1969 Evinrude 55hp Stator Test

The low speed needles are in great condition due to the fact that they have needle valve bearings at the receptacle. I also inspected the receptacles when I rebuilt the carbs (they're fine).

The carb linkages have been checked and are properly synched. The rectifier is good.

I have previously cleaned and properly gapped the points (on each lobe). The compression isn't off by more than 5psi and an average of 135psi across the three cylinders. The wires are in good shape (I changed one because it had rubbed the housing somewhat but not completely through).

GB