In Samarin (1967) I glossed fun' as 'to smell', but I meant that something smells (intransitive). Ma takes an object, because it means something like 'perceive with hearing and smelling' (with the ears and nose); fun' means 'be rotten' (French pourri), 'exude an odor, usually bad', even without sioni 'bad'.
Source: Samarin 1967: 212