My bike has 137K miles, and symptoms of surging, difficulty in balancing TBs and increasing idle speeds has been present for about 15-20K in retrospect. . . The shops and I failed to diagnose the true problem until I noticed the chatter on this last tune-up. (Kit Sold)

Did the repair yesterday (Kit Installed).The shafts and bearings were worn about equally; minimal wear on the right TB, and I’d guess about 40 thousandths on the left, mostly confined to the pulley side of the shaft.  (That’s an estimate – it felt a little more wiggly than my exhaust valve clearances, which is 30 thousandths).  The wear was much less than I expected, certainly less than that illustrated. But the bike seems to run much better, with little to no surging, and repeatable TPS measurements.  I think that fixed the problem.  I expect that having new shafts will slow the wear on the associated bearings also.

Thanks again for your expeditious service and help.

Cheers, Nick