I have tried to start it while holding the gas pedal about half open and that seems to work. I starts with a bang and pop and then races until I let off on the gas. I think this indicates more air is needed or too much raw gas is in the manifold.
I tried leaning out the idle mixture screws (tightening them) on the three carbs. Finally got it to restart hot when the screws were set at 1/2 turn out from the closed position.
