I now believe that your original tank was aluminum.
My 1923 and 1924 N 4225 motors both have brass tanks and both have the sn plate on the brass tank, with no rivet holes in the reverse housing where a sn plate could have been attached. My1924 N 6414 motor has the aluminum tank with the sn tag riveted onto the front of the reverse housing.
Since your N 5166 has the rivet holes in the front edge of your remaining portion of the reverse housing, indicating an aluminum tank, it appears that the brass tanks ended somewhere between N 4225 and N 5166.
good info "Hotrod"
I thought that the copper tank always belongs to the NS model with
the salt water / brass lower unit
thanks for sharing
😉
I also found a Tag from The Ohio Conservation Place dated 1942. You can see it above the Tilt adjusting arms. It has a number on it. I would try and look the person up, but maybe the family would want the motor back….LOL
Most opposed twins are tested by connecting the 2 leads of your meter to the 2 spark plug wires. When your analog meter is set on the 1000 ohm scale, the reading is usually somewhere between 5000-15000 ohms for a good coil winding. This doesn’t test the insulation but that seldom needs testing except visually.
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