I don't think they are any better or worse than any of the later (K1 onwards) K series carbs. The F1 carbs as standard gave smaller main jets 105 as opposed to 120 in the K series, but that was down to the stock 4 into 1 exhaust. At some point in K production the tickover adjusting screw moved from one side to the other, the F1 being the same side as the later K's.
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