Ignition Spares

Just bought a used ignition coil ?

Some people have the illusion that buying 50/60 year old coils are a bargain, WRONG, most if not all around that age are full of rotten green copper wire no thicker than a human hair, If you test one with a multi meter & find a circuit through the windings it still doesn’t mean it will function properly, some don’t show a circuit & still make a spark, WHY?, because the current is jumping across a break in the windings & very soon that gap will widen after getting hot and the current wont jump anymore & the coil will fail, Also some will show a spark at a plug laying on the engine, but when you screw the plug in it wont spark under compression, the compression can stifle the spark if its weak.