[mr0077]

I'm leaning toward Poorboy's idea of a manifold leak at/near the #1 runner. Try spraying WD40 around the intake gasket and see if there is a change. Another long shot, could the motor have swallowed something that is disrupting fuel (but not air?) to #1? How would you check THAT!? Maybe 750 is on to it, check the rocker movements on #1 and #2 with a dial indicator, maybe a lobe has gone, but not completely. Let us know, interesting (frustrating) problem.