How old is the ignition coil?
I had very similar experiences when my died, it sounded like it was running on 3 cylinders, no power, and would not rev about 3k, then got steadily worse.
Changing the coil it was back to normal... if you can borrow one to see if it is this, then it saves you the effort of the carb removal etc....
Jon
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Ital or Ford... the choice is yours....
Hmmm, I'll have the ford please Bob.