I can't remember if 488 recordings are backwards compatible to the 4-track decks (234, 244, 246, 414, 424, etc. etc. etc.) I know you can play the 4 track recordings on the 488. Try tracking to tracks 1, 3, 5, and 7, OR tracks 2, 4, 6, and 8. The tracks are staggered on the 488, the odd ones at one position and the even ones at another position. The Tascam 8-track cassette decks feature circuitry to the sync the tracks. They did this to reduce crosstalk due to the close proximity of the heads. Yamaha followed suit.
Do you have the manual to your 488? I haven't got my copy of the manual handy at the moment but maybe I'll look at it later if you don't have one and you get stumped.