1954 25hp no spark

[dtsman]

Hey guys,

Restoring an old 1954 25hp Johnson seahorse.
I can not get the lower spark plug to spark.
Everything is new. I have attached pics.
It seems something should be isolated. Everything I meter shows continuity.

What should the points be connecting??

With points contactors seperated with folded paper pieces.
I meter from the face of coil#1 to the face of coil #2 and show continuity.
I meter from one green wire on coil#1 the the other green wire on coil#2 and show continuity.
I meter from the end of my spark plug wires and everything I touch show continuity. The black wires from the coils are disconnected in the picture only because I am troubleshooting with my meter.

Thanks,
Bo

 

[orbanp]

Re: 1954 25hp no spark

Hi Bo,

One of the low tension coil wires goes to the ground, most probably that is the black (others with more specific knowledge will chime in). The other end of the low tension coil, the green, goes to the breaker point. This coil should have low resistance (couple of ohms). The high tension output should show a couple of Kilo Ohms to the ground (the other end of the high tension coil is connected to the ground wire). The cap is parallel to the points. Remove the coil from the points, open the point (with an insulator like you did), it should read infinite resistance. If it does not, then either the cap is shorted, unlikely if new, or the point is attached incorrectly to the plate, some insulation is missing. Divide and conquer, and you will find what is wrong. If everything seems fine, swap the coil, and other parts from the working ignition.
When both the green and black wires are disconnected, the coil should read infinite resistance to the frame, if not then the coil is internally shorted.
If the coil wires are reversed (green, black) it would still spark, though spark polarity (the polarity of the high voltage that sparks) will be reversed, and it will not have the same intensity.
Here is also a good article: http://www.duckworksmagazine.com/03/r/columns/max/07/index.htm

Good luck, Peter

 

[kfa4303]

Re: 1954 25hp no spark

HI dtsman. Welcome to iboats. Here's another great link to walk you through a magneto rebuild. I've lableled where everything should go in the pic below as well.

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm n

 

[dtsman]

Re: 1954 25hp no spark

Thanks guys,

Been reading the links at the bottom to other similar motors. I switched the condensors, in case one failed internally and I still only have spark on the top cylinder. Points meter continuity when closed as they should. Both the coils meter the same in all directions that I can put my meter leads. So I assume they are good.

I will keep tinkering and post back if I find anything.

Bo

 

[kfa4303]

Re: 1954 25hp no spark

How are the spark plug wires? When/if you install new ones they should be 7mm copper core wires that you then twist onto the coil posts rather than simply poking them in place. If you can't get new wires, try trimming off about 1/2" from the coil end of the old wires to expose from fresh copper. Did you replace the boots on the end of the wires? Have you tried swapping the plugs to see if one may be bad?

 

[dtsman]

Re: 1954 25hp no spark

New plugs, wires, and boots. The wires I don't believe are copper. They are silver. They are what was recommended from the site that I ordered all this stuff from last year.

 

[HighTrim]

Re: 1954 25hp no spark

In pic 3 it looks like the turquoise wire goes to the coil mounting screw??? Or are my eyes playing games on me?

 

[dtsman]

Re: 1954 25hp no spark

that wire i think is the kill wire. I disconnected it from the points connection and just put it there to keep it out of the way. The other end of it is just hanging down under the block. There was an old rotten wire there I replaced. But I thought I remeber it being grounded to the block somewhere and connecting to the points connection.

I ordered points and condesor packet from Napa today and will pick up later this week. I did not replace the points, I only cleaned them. After I cleaned them they looked new. Thought if they ohmed ok, they should be ok. But that is the only thing I have not replaced with new.

Bo

 

[HighTrim]

Re: 1954 25hp no spark

It does connect to the points, the other end to your cutout switch. You will notice the cutout switch also has a 3/16" "fuel" line running from it to the intake. When the motor over revs, the increased negative pressure in the intake manifold closes the switch, which grounds out 1 of your points. You do not want that line to ground to the block like you though, or you would really have no spark.

Are you sure your points are clean? I use a small brush with acetone to ensure they are spotless. Even a fingerprint on them can cause issues. What did you use to dress them? Sandpaper leaves grit embedded in the points, causing no contact situation.

 

[dtsman]

Re: 1954 25hp no spark

Help me to understand points a little better.
I don't understand how dirty points will stop spark.
I thought points grounded the coil so it could not spark, and the plug is allowed to spark when the point opens.

So if I prop the point open, the plug should spark everytime the magneto goes by??

But as i mentioned earlier, I have continuity across the points even with them opened.

Bo

 

[HighTrim]

Re: 1954 25hp no spark

Im not the best guy to explain this, F_R on someone more knowledgeable could explain it better, but a quick simple explanation is when the points open, it collapses the electrical field in the primary windings of the ignition coil. This induces voltage into the secondary windings that boost the voltage and fire the plug. Your condenser is there to deal with the voltage surge that causes points to arc/burn. As the points open, it stores the energy and it releases it when the points close.

You have continuity across the points with them open, and disconnected?

 

[nwcove]

Re: 1954 25hp no spark

HI dtsman. Welcome to iboats. Here's another great link to walk you through a magneto rebuild. I've lableled where everything should go in the pic below as well.

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm n

View attachment 146401

just to clarify, is the keyway in the crank the high spot on the points cam, or is it where its stamped "top'? ( isnt the stamped " top" merely there to keep that part from being installed upside down?)

 

[HighTrim]

Re: 1954 25hp no spark

just to clarify, is the keyway in the crank the high spot on the points cam, or is it where its stamped "top'? ( isnt the stamped " top" merely there to keep that part from being installed upside down?)

They were labelled TOP, then changed to SET years later. Usually the high point is the flywheel key.

I myself have stopped using that method since I have aquired a timing fixture. If you do use that method, whereabouts along the word do you align? You would be surprised how far out you can be when you are relying on a) a feeler gauge and human touch and b) your eyesight to align the points. Timing fixture and analog meter sets them exact and more importantly, 180 degrees apart.

 

[kfa4303]

Re: 1954 25hp no spark

+1. TOP just meant right side up, but does loosely correlate to the high spot on the crankshaft cam. Of course, the points should be set when the points are at their widest, or even better using High Trim's method. I suppose the silver spark plug wires would work, assuming they're solid core, but that seems unlikely. If they're automotive, graphite based wires they will not work properly. Most OMC dealers carry 7mm copper core wire on large spools and will sell it by the foot. You can also find it at some auto parts store, or right here on iboats. I would remove the turquoise wire for now, just to remove a variable. You can easily add a push button lanyard kill switch later.

 

[dtsman]

Re: 1954 25hp no spark

Thanks hightrim,

I understand now. The coil charges when points are closed, so my coil may not be charging with defective contact points. I will be changing the points and condensors by the weekend to see if that helps. I will check with them when there for an upgraded sparkplug wire.

I will be leaving for an out of town job in the morning and be back in 2 days to start at it again.

Bo

 

[dtsman]

Re: 1954 25hp no spark

OK. It appears I have a bad coil out of the box.

I bought new points from Napa.
They were noticeably better than the originals that I just cleaned. Should have done that in the first place.
Still no spark.

I followed the procedure shown by D. Penn on youtube on how they should meter.
They both meter the same. They show 7k ohms from the sparkplug wire to the black wire on the coil.
The black and green show shorted.

So, I took the whole plate back off and switched the coils from one position to the other.
Now the bottom plug sparks and not the top. uggggh.

I ordered this stuff last year, don't know where my receipt is, and not sure if it is still under any kind of warranty if I did know where the receipt was.
I will now have to order another coil.

Thanks for all the help. I will post back if that does not fix it and I move on to something else. But this appears to be obvious.

Bo

 

[1946Zephyr]

Re: 1954 25hp no spark

A bad coil out of the box? Darn. That can have you pulling your hair out after a while.

 

[HighTrim]

Re: 1954 25hp no spark

Rare but happens. At least you figured it out.

 

[dtsman]

Re: 1954 25hp no spark

Put the new coil in and got spark.

Would only run on high speed. I am thinking my gas mix may need to be leaner. I mixed it 24:1 by putting 2 of those small 2 cycle oil bottles in with one gallon of gas. The garbage can I used showed alot of oil after getting it to run once. Now can not get it started again.

Thanks for the feedback on the electrical issue. Can't believe a new coil metered good and wasn't.

Bo

 

[HighTrim]

Re: 1954 25hp no spark

What is the compression on the motor?

Glad you got spark. Partway there now!

24:1 is fine for that motor, I would not lean out the mix.

The oil in the test tank is normal, no way around it.

Have you been through the carb?