ignition fix

[joe-smerc]

Need to set up old outboard to use Outside 12v ignition coil… any clues How to do That?? thanks tetonboatermotor

[jw-in-dixie]

Not wanting to invest $100+ in Bendix coils in a Mark 20 powerhead that I wanted to use on a rat motor, I hung a pair of motorcycle coils onto the block, removed the old coils, left the capacitors as they were, wired the points to the m/c coils and a mower battery and ran it that way. Ran great. JW

[Tom]

You can also put the original bad coils back in, assuming the primaries are OK. Cut off the secondary coils first. Run one wire to ground, run the other out out the bottom of the mag plate. Also, run a wire from the points out the bottom of the mag plate. Then mount OMC coils somewhere under the cover, on the block. Connect one OMC wire to the wires coming from the primaries of the B-S coils. Connect the other to the wire coming from the points. This basically puts the primary of the OMC coil in series with the primary of the B-S coil. Run secondary wire to the secondary of the OMC coil to the plug.

This allows you to maintain magneto ignition, you don’t need to carry a battery.

I did this with a Merc 5 hp, and it ran fine.

Tom

[jw-in-dixie]

Tom, I wondered about that but did not try it. Glad you chimed in. Learned something. Thx, JW

[mercuryman]

I tried this today and got very weak spark. Then I tried another Bendix coil without cutting off the secondary and it worked better. I guess my primary was shorted. Then I tried the German OMC coil and it worked very good , but what to do with spark lead. The light green plastic cover coils will just clear the rotating magnet. The old style coils are larger and will hit magnet. I could turn coil over and drill through mag. for spark wire but not ready to ruin a good mag plate. I need to find another bad Bendix coil and try for spark at the OMC coil.

---

Attachments:

[garry-in-michigan]

If it works, it’s not ruined . . . 😉

[Tubs]

If you cut off the sleeve and solder the wire on
you may be able to mount the coil differently
on the laminates to get the wire to where it
exits or possibly drill a new one. If you think
this is worth trying put some goober on the
solder joint to keep it from arcing.

Here is how sbrown21 attached the wire on the motor
he was working on-

" Cut the sleeve off turned it upside down used the coil
pin like a sparkplug connector through the side of the
plug wire and put a zip tie around the coil to hold in place."

Give it some thought.
You may be able to come up with something better.

A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.

[Author]

Posts