Honda HS621 Owner's Manual page 35

3.Slide the cable boot upward. The drive belt should be adjusted if the
lengh "A" of the drive belt tension spring is less than 30 mm (1.18 in)
with the auger clutch lever squeezed fully. If adjustment is required,
consult your authorized Honda dealer.
CLUTCH CABLE
BELT TENSI
CABLE BOOT
34