On the older (WPC and older SS) games, they lasted tens of thousands games.

Mushrooming means the top of coilstop or the end of plunger starts breaking apart and spreading.

Mushrooming is not on the coil stop, it's on the plunger.
Thousands of times slamming against the stop cause the plunger tip to flatten out and mushroom.

So its kind of a known issue that the coil stops stern has been using for the last few years are absolute crap. After 500 or so plays most break. The replacements you get made by anyone else will last for literally thousands of games. I've seen games on route continuously since the 1970s (like the ones at Crabtowne USA) that still have their original coil stops. Longs story short, if you switch out the Stern coil stops when they break and put new ones in, some hobbiest in 40 years who buys your pin at an estate sale might decide to replace your coil stops, but you won't.

You see how each influences the other....

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The problem you are having is something quite recent in pinball, and it appears to me that the brass alloy that a Stern's supplier is using is too brittle in the construction of the coil stop.

With a modest amount of hits, the brass of the coil stop shatters into little bits of shiny metal dust that hits the bottom of the game, allowing the 'slug' to be loose and eventually cause flipper problems.

I suspect that Stern is getting parts from multiple suppliers, because as a Stern Dealer, I've had batches of Stern Pinballs come in with no problems and batches of Stern pinballs come in that every machine has compromised coil stops.

I think you were just unlucky, and got some parts that weren't made with the right materials.

It's annoying. But it's not the hardest thing to fix. With replacement coil stops (I buy from Pinball Life), four year old games that have had a LOT of play don't have flipper coil stop problems... yet.

Eventually they'll get pounded down and I'll rebuild the flippers, but this is usually after several years of use.

What issues did you have? A lot of people read about coil stop problems and get paranoid and potentially replace good parts.

I can see that side of it. And I can also see the side of just throwing in new Coil Stops when you get the game...same as Balls.

While a coil stop is nothing cost wise - I feel like Pinside creates epidemics of problems people don’t have. Almost like Pinball hypochondriacs.

People pre-buy cooling fans and other products and fix things that aren’t broken before they even play their NIB game.

And to be clear - I know flipper fade exists in some games but I challenge how many people needed to fix the problem or even noticed it or was impacted by it. People pre bought these fans on the new Stranger Things only to discover that Stern improved the issue and the coils weren’t heating up as quickly.

Haha...I'm with you 1000%

I'm on record posting aboot how pin fan folk are the fucking worst & their "scary graphs with red jagged lines showing heat"...whatever that means.
Did you knowm Novus abrasive is an abrasive?!? I mean people hear literally say not to use novus and plastics cause it's a plastic cleaner

Stern coil stops have a high rate of suckage. Stern balls suck. I'm not gonna raise an eyebrow if people want to replace them from jump street. Now....the people that replace balls every 200 plays