All the K4 should need is:
4 bowl gaskets.
8 O-rings for the fuel tees, 7.9x1.9mm minimum, 8x2mm OK.
A 26mm float gage (made one from cardboard).
A razor blade to clear off the tiny burrs on the insides of the float support arms, so they won't overflow on the sidestand and leak again, later.
These carbs don't wear out, except for the occasional corroded float valve if the carbs sit dry too long. If you use Keyster float valves, try setting the floats at 25mm or 24mm instead of 26mm, as their springs are too stiff and the float level ends up being too low as the result.
This year alone, I've refurbished 5 sets of 7A and 657 carbs: none have needed anything more than mentioned above, except a few needed to have the jets drilled back out (with proper size drill bits) to clear the corrosion inside. They all worked fine afterward.
