1960 75 hp Evinrude distributor/magneto question

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

Well, after a weekend of *ahem* clearing my head, I took a fresh look at my distributor.
I found a picture I took of the points and condenser before dis-assembly and replacement (Attached).
I wanted to compare the before and after picture (Also attached). Everything looked fine, so I began to poke around and discovered something odd;

With the points closed, there is no current moving across the point set. These are the newly installed points. I checked to see if they were fully closed, and they are touching, but with my ohm meter on each point, there is no reading. No current.
Can anyone explain how two pieces of metal touching each other are not moving a current? I'm not a rocket scientist, but I can tie my own shoes. What am I missing here?

I expect a couple of questions about the basic things: They really are touching (I closed a piece of tissue paper between them and it stays when tugged on).
They have been cleaned with alcohol.
They are brand new.
The brass clips are in place.

Granted, I've never replaced a set of points on a two stroke before, and it's beginning to show.

Before:


After:


I'm stumped again...
Thanks in advance :redface:
Bill

 

[Joe Reeves]

Re: 1960 75 hp Evinrude distributor/magneto question

Make no attempt to test current. You simply want to test the resistance reading, continuity.... OHMS. What is your meter set on?

 

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

Yes, current might not have been the best choice of words. I was testing for resistance.

The ohm meter was set at the 20k setting. When both sides of the points were touched (when closed), there was no change on the meter.

Unlike when both leads are touching, or both leads are touching one piece of metal.

Sorry for the confusion.
Bill

 

[samo_ott]

Re: 1960 75 hp Evinrude distributor/magneto question

This a great thread. I don't have the engine yet but expect to one day.

 

[Joe Reeves]

Re: 1960 75 hp Evinrude distributor/magneto question

I don't see how that's possible so I'm going to back out of this posting.

 

[AlTn]

Re: 1960 75 hp Evinrude distributor/magneto question

suggest removing any other wires from the points then testing the resistance when closed..gonna be some < 1 ohm, more like .25 ohm probably....if much higher remove them from the plate and clean them with acetone or file them shiny, there really should be almost no resistance between them when closed... are you certain that they are fully closing?

 

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

I don't see how that's possible so I'm going to back out of this posting.

Thanks for all of your help through this issue Joe.
I hope I can post a successful conclusion to this.
Much obliged,

Bill

 

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

suggest removing any other wires from the points then testing the resistance when closed..gonna be some < 1 ohm, more like .25 ohm probably....if much higher remove them from the plate and clean them with acetone

Yes, I think removing, cleaning and resetting them is the next logical step.
I'll try to check them without the wires connected as well.

Thanks,
Bill

 

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

So I decided to remove the points I had installed.
Regardless the issue, the fact there was no current (or full resistance) between the closed points was too much for me to accept.
I dug up the old burned points I had removed and re-installed them.

What do you know, they had no resistance when closed, and allowed the button on the top of the coil to throw a nice healthy spark!
I put the cap back on the distributor, plug wires and plugs, and the plug snapped a loud, bright spark when grounded to the distributor case.

I have no idea why a brand new, clean and clear set of points would not work, but I now know the reason I had no spark.
I'll do a bench test on those new points with my wife and set the issue straight.
Thanks all for your help.

Bill

 

[Willyclay]

Re: 1960 75 hp Evinrude distributor/magneto question

They are brand new. Bill

I am no expert as described in my signature and when one of the forum gurus like Joe Reeves drops out, I am very hestitant to make any comments. However, another member reported weird results when testing his "new" points which after being replaced with OEM parts, all his problems went away. That thread makes me ask what brand of points did you buy? Are they NOS-OMC, new-BRP or some aftermarket brand like Sierra? Just curious because I have the same magneto needing a rebuild. Good luck!

 

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

The points I bought were new/old stock OMC parts.
It turns out after some serious testing of the points, that they had either been coated with something or had covered themselves over 50 years in the box with some kind of corrosion (that was not rust, as it was the same color of dull matte finished metal).
Maybe someone more in the know about these old factory parts may know what was on the face of the points, I could never figure it out.

I took the points apart and tested each side of one point set with an ohm meter for resistance.

With both tester leads touching the face on one side of a point set I got full resistance. The lead tips were 2 mm apart, on the face of the same point!
If I touched the outer edges of that same point I got no resistance. The face of the point apparently had something on it that was totally preventing conductivity.
I polished the face of the point with very fine sandpaper, until it shined, and it solved the problem.
So although Joe said my issue was 'not possible' (with all due respect to an expert and very nice man) it was possible and definitely was happening.

The point faces, even when touching each other were not allowing current to pass, due to whatever had been on the faces of the points.
Once polished, they work fine.

That said, without Joe's help I would still be totally lost, and had far less knowledge of the magneto system than I do now.
I hope this thread helps other users in this forum, and incidentally, the motor is running stronger than ever!

Thanks all for your help and suggestions,
Bill

 

[tx1961whaler]

Re: 1960 75 hp Evinrude distributor/magneto question

There were at least 4 posts saying that the points needed to be clean....just sayin....

 

[Joe Reeves]

Re: 1960 75 hp Evinrude distributor/magneto question

Your comment of which I see no reason for existing, of "So although Joe said my issue was 'not possible' (with all due respect to an expert and very nice man) it was possible and definitely was happening." comes across as sort of a slam.

You stated in perhaps not so many words that you had cleaned the points.... and not having continuity thru clean points is an impossibility. If I had been there, I would have picked up on that faulty point covering immediately. I'll avoid comments in the future that might come back to haunt me.

 

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

Wow, sorry this thread had to degenerate into this.

Joe, that wasn't meant as a slam at all. Please excuse the tone of my remark.
I want it known how much I appreciate your effort and time put into this thread, and the knowledge I've taken away from this I owe mostly to you, F_R and a few others.

As for this comment:

There were at least 4 posts saying that the points needed to be clean....just sayin....

You mean including the post where I said I'd cleaned the points with alcohol, right?
I appreciate that positive contribution as well.
Gotta love the 'just sayin' crowd.

Thanks again all for your help with this issue.
Sorry it went down the road it did.
Bill

 

[samo_ott]

Re: 1960 75 hp Evinrude distributor/magneto question

Well I learnt from this thread. Not to trust new points. I'll sand em from now on. Usually I just file down old points though so I have not had this issue.

 

[tx1961whaler]

Re: 1960 75 hp Evinrude distributor/magneto question

Wow, sorry this thread had to degenerate into this.

Joe, that wasn't meant as a slam at all. Please excuse the tone of my remark.
I want it known how much I appreciate your effort and time put into this thread, and the knowledge I've taken away from this I owe mostly to you, J_R and a few others.

As for this comment: You mean including the post where I said I'd cleaned the points with alcohol, right?
I appreciate that positive contribution as well.
Gotta love the 'just sayin' crowd.

Thanks again all for your help with this issue.
Sorry it went down the road it did.
Bill

Wasn't meant as a slam, hence the little smiley things in the post.
You were already receiving very good advice from Joe, so no need for me to jump in on this one.
Glad everything worked out!
Those are marginally good ignitions when running; the cost of replacement caps and rotors are getting prohibitive to keeping those Starflite's alive. I actually liked the later automotive type ones better for distributor-type ignitions.

 

[bilbo1usa]

Re: 1960 75 hp Evinrude distributor/magneto question

Wasn't meant as a slam, hence the little smiley things in the post.

Ah! Good. Thanks!

So you've raised an interesting point;
I've heard some people talk about converting these old style ingitions with parts from an automotive ignition setup?
Is this a possibility?

Just curious.
Bill

 

[tx1961whaler]

Re: 1960 75 hp Evinrude distributor/magneto question

Ah! Good. Thanks!

So you've raised an interesting point;
I've heard some people talk about converting these old style ingitions with parts from an automotive ignition setup?
Is this a possibility?

Just curious.
Bill

I haven't seen the automotive conversion one lately, but there is one guy "durban" that converted the automotive one to CDI:
http://forums.iboats.com/showthread.php?t=527612&p=3584396#post3584396