To address the flipper buzz a bit more and as a PSA for the new pin owners.
The coil stops on the newer sterns don't last nearly as long as you may expect. It's a good idea to have a couple spares on hand as they are pretty cheap and easy to change. You will notice they are held in by a copper looking rivet. Over time that starts to work itself loose and will cause flipper buzz and can actually cause a difference in flipper strength/feel. If you take the stop off and you can spin the piece that goes in the coil the stop is bad. I'd talk about mushroomed stops but I doubt any of the newer Stern stops will last long enough for that. Not complaining, just stating the obvious.
Things I do when a flipper buzzes or starts to feel funny.
- take the coil stop off and check for damage.
- if it spins or is lose replace it
- while in there replace the sleeve and washer spring. For less than $1.50 in extra parts why not put a fresh new ones on now anyways?
- If the plunger is mushroomed, replace it (not real common on home use games). If it's good just give it a good wipe down to clean it.
- Make sure the Spring is on the correct side. It should be on the coil plunger side but often they are on the opposite side. (in red box in picture is where it should go)
- Make sure their is not any binding in the flipper bat itself. Their is a bushing (#10 in picture) that can cause sticking if it gets real dirty. Not common either on HUO games. Also check the gap correctly. You can use a CC or a flipper gap tool. Next time you place an order throw a couple in your cart since they are CHEAP.
- Make sure all mounting brackets are tight when re-assembling
Doing the above will resolve most flipper buzzing or sticking issues.
Stern coil stops (#2 in picture): DO NOT BUY Williams/Bally. They may last longer but the way they mount increases overall flipper travel. They will work but it will change how your game plays. I buy mine in set's of 10 as with the 25% they are only $3 a piece. http://www.pinballlife.com/index.php?p=product&id=274
Flipper Coil Sleeve (#9 in picture): http://www.pinballlife.com/index.php?p=product&id=90
Flipper Coil Spring Washer (#5 in picture): http://www.pinballlife.com/index.php?p=product&id=279
Flipper gap tool (second picture): http://www.marcospecialties.com/pinball-parts/03-8194