1959 Evinrude 50hp ignition trouble. magneto/switch?

[ianmoore]

Hello,
I apologize if this has been answered elsewhere. I looked in the FAQ's of engine repair, and didn't see anything that applied to this old of engines.

I am diving into an old 1959 Evinrude Starflite 50 HP. I have what seems to be a working Magneto, points seem OK, new plugs and cables. I have a good Solenoid, and the engine turns over. I bought a switch for a magneto starting system. I think i have it wired correctly, but feel that everything else being as it is to my amateur eye, i should be getting some juice to the plugs. If I disconnect the magneto wire from the post, i see about 5v, but when connected to the post it is almost nothing.

Can someone check my switch wiring?
I have battery to 'B', Solenoid to 'S', one of the magneto wires(the one that attaches to the points) connected to 'M', and then the other 'M', which is a screw connection, attaches to the engine harness. Choke solenoid is connected to 'C', and nothing is currently connected to the I(ignition).

When i check the switch with the ohm meter, i see that the two 'M's' are grounded in the off position, that the battery and solenoid connect in the 'start' position, and that the 'I' connects to ground in the start position.

We are able to turn the engine over, but not getting any spark at the plugs. I checked the magneto coil and it looks good. The primary is around 1 ohm, and the secondary is around 3-4k ohm. That seems like a working coil to me. The points look good as well. We have new plugs and wires from the coil to the engine.

This leads me to believe that we have something wrong in the wiring of the magneto. I guess i'm still a bit fuzzy about how it works. Should i be seeing 12v at the input post of the Magneto( going to the points? Should my 'M' terminal be hooked up to something other that the way i have it?

Thanks in advance for any tips. Would be good to get a spark!
​Ian

 

[racerone]

The magneto provides it's own power !!!---Do not try to put 12 volts to any magneto wires.

 

[Chris1956]

Maybe the condenser is bad? Maybe the point wires are rubbing against the points cam? There are two sets of points. Are they both gapped at .020 in?

Your wiring sounds OK, but you should never see any voltage on the coil, unless the motor is cranking. BTW- Spinning the distributor pulley by hand should produce a sharp spark. I would remove the distributor cap and check for spark at the coli button. Once you have it there, reinstall the distributor cap and see if it makes it to the spark plugs.

 

[ianmoore]

Thanks for the response!
I checked the condenser. It seems to be good.(does the climbing ohmage thing when i put the meter on it, and performs the same as the condenser in my other magneto) Points seem pretty clean. They are both gapped at about .020". The wires are not grounding out on the point cam. I checked that out. I will clean them a bit tomorrow with some fine sandpaper
I took of the distr cap, and could see a nice blue spark if i kept it about 1/2" from a nice chunk of metal; got a nice shock when i kept my finger on the coil secondary while spinning it! I also tried spinning the coil with a drill and was able to get a small spark from a plug to the housing. It seems that the coil is working.
There was only voltage on the coil when i was cranking the engine.
I'll clean the points, reinstall the coil and try a spark plug tester.. Report back tomorrow