They all skip numbers.... Mikuni...Keihin.
None of them go 1 by 1.
Doesn't matter though.
And I still think something is fishy with the situation.
Describe exactly what happens with a 56 in it.
what do all those do?.
I am thinking there is a problem with your switched 'nozzle and needle' situation.
There is no way an engine goes from 4 stroking.. to too lean.. with a jump of 1 size.
Something else has to be wrong.