Just bought a Diamondback Outlook with the Shimano Tourney Derailleur on the frong and the TX-30 (think it's still part of the Tourney system). Anyway I am just looking for some info on tuning. The bike won't upshift to the highest front gear, and won't downshift to several intermediate gears on the back. There are no tech docs on the shimano website for the Tourney series stuff.
'71 Gitane Super Corsa, '73 Atala Giro d'Italia, '73 Schwinn Super Sport, '76 Viscount Aerospace Pro, '81 Miyata 710, '81 Lotus Classique, '84 Ross Signature 290s, '85 Miele Gara, '87 Miyata 512, '89 Centurion Ironman, many more
The Tourney mechs are at the low end of the Shimano pecking order, but they do indeed work when set up right. The three bikes my wife and daughters ride have TY-30 and TY-33 Tourney groups, and they run pretty good (even the dump find I re-built).
My latest build Miyata has a Tourney front DR (only triple in the bin at the time) and after riding it for a couple of weeks I see no real need to replace it.