Just ran my outboard for a few minutes and tried the breaker. The idea was to protect the boat from an electrical
fire and secondary was to cut out unregulated charging
on very sunny light wind
So at about 1800 rpm
fast idle I was putting out 5.3 amps. Flipped the switch no amps. Flip it back 5.3. No issues.
If you have an outboard in a well or anyway enclosed or inboard of the transom I would highly recommend you fit a breaker so you can turn off the power to the engine when no needed. All the wires under the cowl are very tight and plenty of potential chafe and therefore short spots.
Also potentially a theft protection as if the motor
only like many Yamahas it would be difficult for any thieves to get the boat moving.