I recently bought a pair of Shimano 600 STI brifters off of EBay. The left one seems fine, but the right one seems quite stiff. Pushing the small lever seems ok, but when I shift using the whole brake lever, it requires more force to get it to click over--like it has to push over some obstructing bit of metal or something inside.
I tried dunking the unit in parts cleaner for 20 minutes and oiling it, which didn't seem to do much. This is off the bike--is having it installed (with cable tension on) likely to change anything? Any other ideas? Is this normal for these shifters?