guys gsf list two timing belts? one with 108 teeth (19mm Part No : 131VG0030) and one with 128 teeth (also 19mm Part No : 131VG0040)
any reason why? lol
Round tooth and square tooth, changes over about 92 iirc
change over is 1990, nearly all mk3s will have the round tooth one which is the one with 128 teeth.