Unfortunately, I don't have the original message any more, but one
phenomenon that's stopped me a couple of times is boiling fuel.  If
the fuel line rests on (or runs too close to) the intake manifold,
heat gets conducted to the fluid inside.  Since that fluid is
(relatively) cool, and flowing, it acts as a heat sink.  Eventually,
it starts boiling, and carburetors don't seem to like this a whole
lot.  The way I noticed this was happening was when I opened up the
engine compartment and saw the really neat bubbling going on in the
fuel filter.  Kinda like a lava lamp on espresso.

So, check your fuel line routing, particularly if you have a metal
fuel line.  Of course, if you have a rubber fuel line, you should be
even more paranoid, because rubber melts....

	Dworkin