Mid 70’s OMC. No spark.

[elgin2]

I received for free a mid 70’s Omc outboard with no spark. Been painted. Pretty sure they used a 3 or 4 inch brush so I can’t tell what brand. Model 50RL78S. Checked for continuity of the stator on power pack 2 and got nothing. Should there be continuity there? Thanx in advance.

[jeff-register]

I haven’t worked on anything that new but I’ll try to suggest a few tests. First do you know how to use a multi meter, for starterd the ohms selection? If so go for the 10k selection or 10,000 ohms. The secondary windings almost always fail first. Check with one  probe on the spark plug wire & the other connected to the mag plate. I’m guessing around 5 to 7 K ohms should be the reading. Others here are very good with your 1970 so I will refer to others. May you post a pic of the magneto please? P.S. Check each coil independantly as they are both their own sysyem electrically.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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[elgin2]

I agree. It’s too new for me too. Coils checked out on a Merc o tronic.

[fleetwin]

OK, not seeing this model number on marineengine.com.  Could be a commrecial or international model…

In any event, not totally sure I under stand just what and wear you are testing resistance.    Post some pictures of the engine and point out what leads you are testing for resistance.

When you say “nothing”, I am assuming you mean infinity.

[elgin2]

I pulled the flywheel and found the stator has been hot. Also found on the welsh plug the numbers 50273c and E 12791 making the power head a ‘72 Evinrude I think.

[jeff-register]

Photp please. The stater is just windings correct? Amd magnets in the flywheel? P.S. Your stator may look hot because on insulating varnish that the manufacturer has dipped the windings in insulating solution. Again pic please. Someone advise “hot to do” Hrlp.

[fleetwin]

elgin2 wrote:

I pulled the flywheel and found the stator has been hot. Also found on the welsh plug the numbers 50273c and E 12791 making the power head a ‘72 Evinrude I think.

Not uncommon for those light green stators to have a little drool coming out of them….What reistance reading did you get when you measured the brown leads from the charge coil?  Should be several hundred ohms..  The sensor leads should read around 40ohms. I think the sensor circuit goes through ground on this engine, so you only see one sensor lead, and a ground lead…

[fleetwin]

fleetwin wrote:

elgin2 wrote:

I pulled the flywheel and found the stator has been hot. Also found on the welsh plug the numbers 50273c and E 12791 making the power head a ‘72 Evinrude I think.

Not uncommon for those light green stators to have a little drool coming out of them….What reistance reading did you get when you measured the brown leads from the charge coil?  Should be several hundred ohms..  The sensor leads should read around 40ohms. I think the sensor circuit goes through ground on this engine, so you only see one sensor lead, and a ground lead…

Correction….  I think it is the charge coil that has only one brown lead, the other leg goes through ground.   The sensor coil has two leads.

[elgin2]

I’m getting 3.8 ohms between the yellow leads. I’m not sure how to check the brown lead. Here are some pictures. The coil- looking component appears to have been hot. The brown wire goes to post 1 in power pack 2.

[elgin2]

More pictures

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