My 83.5 w/c Westy is having problems with the hesitation again.  It does it
whether the engine is hot or cold and is intermittent.  What happens is the
power cuts off by about 1/3. It's a smooth power loss, like someone threw on
a switch.  Then it instantaneously regains normal power again.  Every now
and then its like a bucking.  Any suggestions?

Thanks,
Bryan