You may have some luck taking the part number from this site to your local Honda dealer.

If you check out the page for the carb, you'll see that item three is:

float seat:
3 16011-KM9-711 Valve set Float

And 6 the float itself:
7 16014-KM4-004 Top set

You can try putting them into the parts finder on http://www.lings.com/ too.
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