Johnson TD 15 magneto coils

This topic has 11 replies, 3 voices, and was last updated 3 years, 7 months ago by frankr.

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September 19, 2020 at 3:30 pm #216880
ron65v
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I need two magneto coils for a Johnson TD 15 motor. One of the current coils has an open secondary and the other measures 117K in the secondary. The OEM Pn. is 375189. Looking for NOS or used.
Has anyone ever replaced the coil winding on the armature/ laminations with a 50’s style coil?

Thanks for any help

Ron
September 20, 2020 at 8:24 pm #216951
The Boat House
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September 20, 2020 at 11:01 pm #216965
frankr
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This kind.
September 20, 2020 at 11:06 pm #216968
frankr
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As you were measuring the secondary resistance, where were you measuring? See the info concerning maverick spark suppressors. You may not have bad coils after all.
September 21, 2020 at 8:48 am #216983
The Boat House
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- This reply was modified 3 years, 7 months ago by The Boat House.
- This reply was modified 3 years, 7 months ago by The Boat House.
September 22, 2020 at 11:34 am #217073
ron65v
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Thanks your time, great pictures. Saves me a lot of time and expense on parts.
- This reply was modified 3 years, 7 months ago by ron65v.
September 22, 2020 at 11:38 am #217075
ron65v
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Good information.

Thank you,

Ron
September 22, 2020 at 11:53 am #217077
frankr
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Ron, did you understand the maverick spark suppressors? They will show open secondary if not tested properly. There are two ground wires on those coils, one for the primary and one for the secondary.
The secondary connects to the maverick spark suppressors. You must connect your meter between the spark terminal and the SECONDARY GROUND WIRE—not to the armature plate as you normally would..
September 22, 2020 at 9:07 pm #217128
The Boat House
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- This reply was modified 3 years, 7 months ago by The Boat House.
September 22, 2020 at 9:38 pm #217130
ron65v
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Sorry for the delay in responding I was measuring between the ground wire attached to the armature and the secondary out put to the spark plug wire. If I measure between the “Maverake” spark suppressor and the secondary output to the spark plug wire I get about 7.5 K on both coils. I get no spark from either coil when turning motor over with cordless drill. I have removed filed and polished both sets of points and gaped correctly. I also soldered new spark plug wires to the secondary’s The “Rest of the story is this” I originally had about a 1/4″ spark on both coils before I did any work to the magneto other than running sandpaper between the points.
The core pole pieces of the armature were touching the rotor. I gapped them to the correct value. Summary is I screwed something up? Also I ordered two used KD 20 coils from Lloyd Lautner before I read your post. Not sure they will work without the spark suppressor?

Probably replied to wrong post ?
- This reply was modified 3 years, 7 months ago by ron65v.
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