Apache,
If it were mine, at this point I would verify a good strong spark--capable of jumping at least 3/4 inch to ground.
Then I would try to drive it on 1 carb at a time by releasing the connecing linkage leaving one carb at idle.
Of course it won't run normally but it should run and drive on 1 good carb and probably not on the sick one.Then we can go to work on the problem.
