There are three numbers in my parts book, 16950 kv3 830, 16950 kv3 680, and 16950 kv3 681, all for the 21, i would imagine that 16 and 18's have the same tap, and maybe other honda's of that period, ie, cbr, vfr, the only difference being the on off knob which are different lengths, and are removable from the tap body..
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