Yep- this is to some extent normal and in my experience is a feature of Williams flipper design. My Gottlieb games can he adjusted to nearly elminate the slight give and mini flip that occurs on Williams games and Bally also seems somewhat less prone to this in the similar era (late 70’s). I have spent a while trying to adjust this away on my games and cannot- this is also not my first rodeo. Anyone who claims this is not a normal feature of a Williams mid to late 70’s flipper should post a very detailed guide to how they fixed it. I do not desire this behavior and would love to adjust my way out of it.

In my experience there is no gap setting between machine gunning the flipper (too close on EOS) and a flipper that phantom flips if a ball strikes it. I can get my game pretty close but a medium fast ball causes a flip. I have played with return spring tension as well and dont see a route to perfection.

Having said all that- I am sorely tempted to go unwind 20 turns of wire from my hold coils. That would probably fix the issue!! I dont honestly think I can describe any feature of the design that would cause this- but I do know I see it and cannot easily fix it.

Insight from someone who can point to a physical reason or an actualy fix would be welcome for my part. I believe its possible- but I have to say the phenomena is in fact “normal”. Many people have asked this question, many experience this... so I suppose its “normal”.

I should add that an A/C hum is not normal. You need a new plunger and a new coil stop. That will fix that.

Just wanted to clarify that when I said an AC hum should not occur I should have use a work like chatter or something else. I was thinking in my head of a few times I have had a flipper that was loud when held up- more like a buzzing than a hum. That is fixable.

Sounds like your up and running at 100%.

I love my Grand Prix and the flippers on thos game are strong and just seem extra snappy to me. Very enjoyable game- enjoy ripping the spinners with your new flipper rebuild!