Coil replacement (or not)

[Jazzbouche]

Quick, (and probably basic) question: am I right in saying that a coil either works or does not work - there is no in between?

As in, is there any point to replacing coils which are clearly old (and look a bit crispy from the outside) but that are still working? Will there be any noticeable performance benefit?

 

[Moonbus]

I use the rule, “if it isn’t broke, don’t fix it”.
You can test the resistance of coils against this chart to see if they are good or not...
https://www.flippers.com/coil-resistance.html

If you want to clean them up I use a toothbrush and warm water mostly but have also put them through the ultrasonic cleaner and the dishwasher.
Only time I would replace coils that test good are if they have bent metal sleeves (old EM coils) or the plastic body has been deformed preventing smooth operation.