I have a Gottlieb Rock that I recently picked up as well. Like you, I'm looking at strengthening the flippers and I think I'm going to start with a flipper rebuild. However, I've noticed that the response time seems to be a bit sluggish as well...and no, it's not me...haha. Specifically, if I let the ball roll down the flipper to try for the spinners, it generally craps out and lands on the lower kickers.

Did you ever rebuild your flippers? If so, what was the effect? Did you get a bigger coil? I'm worried about destroying the drop targets if I do that.

On another note, I'm considering modifying a few things on the playfield out of frustration. I really like the game but think it could have been great if a few things were better. Because you have to shoot the drop targets to advance letters, I don't like the random bounces that seem to end up in the outlanes so quickly. I was thinking of moving the lower post down an inch and stretching a rubber between the posts. Don't want to stop everything just make it a bit more fair.

And...have you figured out a way to hit the right lane with consistency (the one just to the right of the spinner)? That's another thing I was thinking of modifying so you could actually shoot for it. That it, I'm done...haha

That's interesting as I was getting a bad air ball on the furthest right drop target. It would launch so badly that it would hit the glass hard to the point I had to stop before it broke and try to figure things out. In my case, I replaced the old, thin black rubber ring with a new, thick white one. I also bent the bar behind the drop target forward...problem solved...for now anyway.

Regarding the flippers, did you rebuild yours? If you did, do you find that the flippers are strong enough now?

There's a lot of good information here. I've only worked on Williams/Bally machines prior and don't haven any experience with Gottlieb's directly powered flipper coils...this info is very helpful. I've just put in an order for the flipper rebuild kit and will also replace my flipper switches as i can see they are in sad shape...I'm sure the game will play much different after the rebuild.

Since this topic has just about covered everything anyone should need to know about flippers on Gottlieb Sys80 games, I have a couple more questions that haven't been touched on. Does it matter which terminal wire from the EOS switch gets connected to the middle (low power) lug on the coil? I was thinking that there might be a reduction in arching if it was wired one way vs the other?

Catching and holding the ball seems to be hindered by the amount of flipper travel. I recently cleaned up one of the flipper assemblies and noticed a couple of holes at the back of the flipper bracket assembly. My thinking was that they must be for flipper rubber stops and installed one. I really seem to have hindered the travel now and being that the plunger is made of plastic, thought it unnecessary to install??

As a bit of an update on the Rock flipper rebuild in hopes that it might help the next guy. After ordering and installing a Sys80 mini flipper rebuild kit from Pinball Resource, I was still lacking power...grrr. Further, the flipper seemed as though it was slow to return. I thought maybe the bushings were too tight on the shaft or it was sticking due to the shaft having some corrosion. After a good shine on the buffing wheel, there was little difference. At this point I've purposely not replaced the EOS switch or Flipper switch. I wanted to see if the plunger, bushings and coil sleeve were the culprits. The power was better but it was still crapping out on outside spinner lane shot.

After taking it out of the machine and really trying to figure out why it felt sticky, I noted the bushing didn't seem to sit exactly straight. I reseated it, tried, then tried the other bushing in the kit but it still had the same problem. Got out my calipers and I noticed that the space in the bracket (that holds the upper bushing to the main body) was bent. I suspect this was from unseizing the flipper adjustment with the allan key?? Anyway, straightened the bracket and the flipper mechanism now runs smoothly. Indecently, my wear on the flipper parts was very bad now that I compare it to the new parts.

In trying the new flipper rebuild out, the outside spinner shot is now makeable sometimes but it still feels like it can barely do it. I'm going to replace the EOS switch before replacing the Flipper switch and see how much difference that makes. If neither switch makes much difference, I'm going to test the resistance on the coil one more time then replace with a new one....I'll get there eventually. I want to do this systematically so I can see first hand how much difference each part can make.

Flippers have now been completely rebuilt. When I did the EOS switch, even though the switch was badly pitted, the improvement was only marginal. The flippers did seem a bit more responsive and had a nicer overall feel to them. But that outside lane shot didn't seem to improve in the way of power.

I then replaced the flipper switch...again marginal if anything and the switch was also pitted pretty bad previous that. I should note that the week earlier I ran a points file over all the switch contacts so that is likely why I'm not seeing much increase in performance there.

Next I took the coil out, checked the resistance against the new coil and the resistances were nearly identical (2.1 and 41ohms). I changed out the coil anyway. Again, nothing really all that noticeable...I think I'll put the old coil back in and save the new one for something else.

Lastly, I disconnected the upper right flipper that shares the power with the lower. There I did notice a slight improvement...enough that it makes me think to replace the flipper wire with a heavier gauge wire to see what improvements can be gained...we'll see, I have some other games that need attention too.

In the end, I connected everything back up and played several games. Overall the game was much more responsive and punchier. The outside shot is still not an option when the ball rolls quickly down behind the slingshot but I'm starting to think this is just a physics thing. I don't think there's enough power generated from the start of the coils stroke to lift the ball at the end of the flipper when the ball is traveling quickly. If I catch the ball and let it roll down slowly, I can make the outside shot every time....couldn't do that before the flipper rebuild. Guess I'll have to live with it but really wanted to hit that outside shot when the ball came down behind the slingshot.

Anyway, there you have it in case you were wondering.

MR2xbass...yes, paid special attention to the EOS switch gaps. Have it currently set to about 1/16" just to make sure that wasn't the problem.

WhySnow...I had two new coil sleeves in the mix. 1 replacement sleeve with the old coil and a new coil and sleeve when I swapped it out...no difference there.

Thanks for the suggestions though, guys. I'm always willing to try just about anything to improve game play. Indecently, my wife thinks it plays just fine and I'm being "fussy"...she's probably right but that's the way I roll...stickler for details.