Lauson Sport King 1947 OB 410

[joecb]

OOPS ! please disregard my last message talking about the “twin coil” magneto. I realize now that you have a Lauson Single. My comments about coil substitutions pertain to the Lauson twin cylinder motors. I got side tracked by reading your posts to that older Lauson thread, that did indeed pertain to a twin cylinder model. I do not have first hand expierence with the single cylinder model, so I’ll defer to others on “no spark” issues.

Sorry about the confusion..

Joe B

[jeff-register]

No spark: Remove both spark plug wires & using a meter set on 10K ohms scale put either meter lead on each plug wire & see what the resistance is. If your motor was run with a plug wire off it may have damaged the coil. Should read about 8  to 10 K resistance. If it is infinate it’s bad, The secondary winding has two ends to the winding & both are spark plug wires. One fires when the coil fires  & the coil has enough electrical energy still & “sees” the first plug going to ground  thru the plug gap, the resistance now goes down & fires the other spark plug in a mirco second. If you have around 10K residtance, your coil is more than likely good.

Good luck

[joecb]

Jeff, with due respect, you are describing a twin , floating secondary coil arrangement. I was off on that track too, and causing the OP confusion. The subject Lauson is a single cylinder motor.

See my previous post.

Joe B

[Tubs]

Gary Peterson wrote:

Hello…well we finally got the 1947 Lauson Sport King A410, cleaned up. My husband rebuilt the carburetor, put in a new single spark plug, cleaned everything he could and put in the gas and oil. He was able to “ spin” the motor but there was no spark at all. What should he check next? ( The little propeller sure looked cute while spinning around🙂)

 

 

 

Mrs. G,
If I’m not mistaken this is the magneto you have.
.


First Gary should clean the contacts with some fine sand
paper (around 400 grit) if he hasn’t already. It would be a
good idea to remove the wires to the points and clean all
that’s there to be sure you have good contact.
Here is a link on how to check your coil-
https://youtu.be/xPd8nMBTCkI
Replacement coils would only be available from other motors.
It is possible to make a replacement using a coil that is still
available but it requires considerable modification to the metal
plates of your original coil. I’ve done it but need to edit the
pictures for a video.
Tubs.

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

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