Last year I bought a 1984 R80st. Bike had about 85k showing, but had documentation dating back to warranty work in 1985, it came with it's own 3-ring binder of records. Along with the records were a boat load of extra parts and cables some new, some parts, some used, none the less all came with the bike. The bike had sat for a few years before the previous owner decided he was ready to part with it. Unfortunately, it was not stored properly, so the carbs and other systems needed to be refreshed. I ordered a carb rebuild kit from Bing Carbs to include gaskets, o-rings, needles and needle jets. While waiting for the kit to arrive, I started going through the cadre of parts that came with the bike and noticed that the PO had ordered Bing rebuild kits three times in the past as well. The Bing plastic bags were in the extra parts cash. Each if the three plastic bags contained two o-rings and four Butterfly screws. I thought it odd that most likely over 85k miles and three carb rebuilds, no one replaced the Butterfly Shaft O-Rings. I pulled the carbs and relized the problem right away. It seems that at some point, most likely during the first carb overhaul, someone mangled the Slotted Screw heads of the Butterfly Shaft to the point the screws can not be removed with a screw driver. Does anyone have a sure fire method to remove these damaged screws? I certianly do not want to have to buy new Throttle Shafts to remedy this problem. I'm sure the Throttle Shaft O-rings have not been changed since 1984, my logical mind is telling me they probably need attention. ANYONE?