[sastanley]

Lubr,
When I switched to EI I forgot to remember to service the advance weights..If they get stuck in the out (advanced) position because the springs can't pull them back in due to a dry rusty non-lubed environment under the EI plate, it runs great at WOT, but the engine won't idle..

However, you said it ran for a second with motor crack, so I wouldn't blame the weights just yet. Next thing I would do is open the drain plug in the carb bowl and pump a few ounces of fuel into a container with the bale on the mech pump and see what it looks like..sometimes adding a component (fuel filter), or disturbing the fuel lines upstream can dislodge crud and block the little tiny holes in the carb.
If the fuel pump bowl was full after the filter was added, the mech pump should fill the filter before the carb burns all the fuel in the pump.