Sorry, long...Have recently located this forum and want to thank all of you for giving me resources and incentive to bring back my lost skills. Also read C.H's PinRepair website fully (some sections more than once) thanks to locating it here on this forum.
Have 4 machines currently in my game room: Big Hit, Target Alpha, Big Indian and Jumping Jack. I shopped all early 80's, did complete PF take-downs and were fully functional. They have since fallen in to disrepair and when guests come over they barely work so I'm gathering supplies and parts. I still have all my tools and needed specialty items like files, burnishers, benders, etc. And since I'm part-time now and our office volume is decreased by Covid-19 have some spare time.
I've started on Big Hit. All the stepper units are gummed up w ancient lube and that appears to be the main issue. So I bought a gallon of 99% isopropyl, a tube of TTF lube and went to work. I am putting together an order from PBR for parts. I'm going to replace tired barrel and shooter springs plus buy a couple of extra wiper springs. My question is the spring kits KT-GSTEP -01,02,04,05 they sell which appear to be the ones I need for my games. Any opinions on springs that are particularly problematic/weak/prone to failure I should replace now when I disassemble the various units? Or should I start by simply buying one of each kit and just see how they look/appear to provide the advance or return function as I go through them replacing only the 'buggered, broken' springs?