Retro fitting modern coils onto old laminates

[sdgloo]

Motor in question; 1937 Evinrude Sport Four #9022

one of the two, two spark coils is bad and I’ve not been able to find a replacement. My plan is to install two BRP coils on the old laminates. The original laminates are shaped something like a dog bone and the original windings were wound directly on them. To install the modern coils I will need to disassemble and modify the laminates. Will reducing the size of the smaller, trailing end have a negative effect on field generation and collapse? Any advice on alternative approaches? Thanks

[frankr]

If I follow your plan correctly, I would say yes to a negative effect. Not only that. the location of the edges of the laminates as the magnets approach and leave (called the “edge gap”) is important.

[Tubs]

Tubs

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

[sdgloo]

Thank you Tubs! That was exactly the approach I had in mind! I disassembled the laminates and found that by striking one with a sharp cold chisel, I could snap it in half without loosing that saw blade width of material. There’s also a rivet at midpoint so I can get a nice tight assembly. Thank you

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