I could not figure out why the starter would not activate on a B-80 i was working on. The solenoid clicked strongly, so I immediately suspected my wiring skills as I was also working on a forest of not so great previous repairs held on by electrical tape as the splice medium.
Finally, I checked the continuity across the lugs and it was apparent that the thing was not making contact. Same thing happened when i robbed a ' last year known working solenoid" taken from a blown engine. That old Solenoid was an original, so i simply drilled a small hole through the metal cap at the end opposite the starting lug connections. I placed the little red straw through the Deep Creep can and fired some of the penetrant through the hole. Five minutes later i had a fully functioning American made factory original good for another forty years.
Beats buying a chinese replacement any day. The first solenoid from the B-80 was a former replacement did not respond to the deep creep treatment, so maybe it will get an autopsy. So lesson learned is to not trust a solenoid that clicks because the thing may be stuck internally