Carl;
(assuming the idle trim screws have no effect on idle at this point? If not...)
Remove the carb from the engine, then remove the trim screws from the metering block (don't lose the cork seals) and give it a good blast of carb cleaner, followed up with a shot of compressed air. You should see carb cleaner squirt from both the idle air bleeds inside the choke tower and the curb idle discharge ports on the baseplate. If not, it's likely clogged with debris and you'll need to pull it down to clean it.
Eric
p.s.
Thanks for the plug Tom
