Two nights ago, I was having some maintenance done on a friend's r1100gs, a '95. After adding paralever bushings, changing oils and adjusting the valves, it was time for sync. As soon as I started the bike to warm it up, I could hear the clatter on the R/H side, coming from the intake. As I put finger pressure on that side's pulley, the ticking sound stopped.
Since it was late and we had no time to fix the TB, I just tried to sync the bike with the intake as it was. For idle speed, all was fine, but when it came to syncing it @ 2500 rpm, it would just fluctuate. I was using the Harmonizer that I got from an inmate here - it's a very nice tool and easy to use.
So as I was setting the cable right, if I came back at idle speed and then back to 2500rpm or above, the bike was every time out of sync, indicating values for about 40 50 mbar on one side. Adjusting it again, dropping at idle and then revved again, the Harmonizer would again indicate that the bike was out of sync every time.
The point is that until now, I knew that a clattering intake would make sync close to impossible, but now, I know that for sure.