Another common leaker is that fuel vapor solenoid on the carb.
It's up by the front drivers side of the carb, and has a vac line
going to it. That diaphram gets all gooey from fuel vapors and
starts leaking. I'd almost bet $$$ it's leaking. Might not be his
total problem, but I'd check it.
Overall, his problems do sound like a big vac leak.
DON'T change all the vacuum hoses.  Why? Cuz if you do, plan
on breaking about half the plastic line connectors as you try to
take the rubber lines off the plastic connectors and Tee's.
Only change the ones you know are bad, unless you have a
pack of new Tees and connectors, etc.. You can buy those at
auto parts. Also, I think by now your idle settings are all goofed
up trying to get it to run. So once you get the real problem fixed,
you will probably need to reset all the idle settings back to normal.
In general, if the car runs ok at speed, but won't idle, it's usually a
vac leak, but can also be a clogged idle circuit. If I had to bet $$$,
I'd probably bet on a vac leak first. There are many places to have a
leak on a carbed honda. From all the rubber lines, to rubber diaphrams,
to even the carb gasket itself.  Common rubber lines to flake out are
the two short ones on the back of the carb. If you have trouble finding

a leak, you can get carb cleaner, or a bottle of gas that you can spray
a real thin stream, and make it easier to find them. Propane will work
too,
but is not as precise.
IE: if you spray carb cleaner at the base of the carb, and the idle
jumps
up a lot, you are getting close.
But then you have to make sure if it's the gasket or a vacuum hose.
A cracked vac hose near the base can mimic a shot gasket.
When you reset the idle settings, use the factory method exactly
according to the sticker under the hood, or from a manual. You have
at least three adjustments usually. IE: carb stop, controlled idle for
auto tranny in gear, A/C idle up, etc.. Having all these set right is
fairly critical for it running like it should. You normally idle about
750 rpm
or so depending on model.
Cranking idle speeds up to mask other problems is a band aid solution.
Your first mechanic should be flogged for using band aid solutions
to the problem.  All it does is cause more work down the line for
whoever
gets everything back like it should be. And yes, you can tell him I
said that. :/
BTW, it's possible your throttle shafts could be leaking serious air,
but I'd
consider that a last resort as far as checking. Those usually show up
pretty
gradually. But...I have had one on a ford truck that went south in a
days time..
I was on the interstate, and the engine was running great, and it just
died.
I got it going again well enough to get where we were going, but I had
to
install a new carb to get back to Houston. The throttle shafts went
south
real fast due to some defect I guess.  But I don't really suspect this
as
your problem.. Just something to keep in the back of your mind if all
else
fails..
MK