There is no phonetic symbol F. Check the Pullum/Ladusaw Phonetic Symbol Guide or the Handbook of the International Phonetic Association. The Māori phoneme in question was originally apparently pronounced [ɸ], i.e. a bilabial fricative similar to the sound in the Japanese syllable fu, and the labiodental fricative [f], similar to the English consonant, is a more modern development. Since in some accents of English wh is pronounced as voiceless labiovelar approximant [ʍ], it was not a bad choice to represent the original Māori pronounciation: the only difference between the two sounds is the added velar constriction in the English regional pronounciation of wh. Note that F in archaic Greek alphabets was used for [w] (the infamous Digamma), a sound largely lost in Classical Attic Greek, and when the Etruscans needed a sign for their own voiceless [f], they used the spelling FH which is also found in archaic Latin inscriptions. That's the origin story of the letter F. In the end, the modern Latin Alphabet has five letters that all originally go back to the North-West Semitc letter waw: U, V, W, Y and F.
[h] itself is usually voiceless and can render adjacent voiced fricatives or approcimants voiceless (as in the regional pronounciation of English wh mentioned above); in modern English note how the sequence [hj], as in Hugh [hjuː] is often contracted to [ç], essentially an unvoiced [j], phonetically the same consonant as in German ich, a sound English speakers like to pretend they cannot pronounce (they can, and do, they just don't know it).