("Viperdoc" wrote)
Again, this was attributed to "whipping" of the belts by two mechanics, as
a result of the engine being detuned due to a sticking crankshaft
counterweight.

I again questioned why this should occur all of a sudden after changing
the belt at annual, since the previous belt had gone for hundreds of hours
without any indication of a problem. No one had a good answer for this, so
somehow the logic of the crankshaft counterweights being the source of the
problem is a little suspicious.


This sounds like a case for "House" ...or in your case, "Hangar". :-)

If it's easy to get at, and all other things being equal, can you swap
alternators with a known good one (meaning pulley)?


Montblack
http://www.fox.com/house/features/houseisms.htm
"Twenty-year olds fall in and out of love more often than they change their
oil filters. Which they should do more often."
- Fools For Love

"Take this four times a day. And stay off airplanes. They're flying
cesspools."
- Informed Consent