Honda VT750C2B Owner's Manual page 119

Suspension
The spring pre-load adjuster has
5 positions for different load or riding
conditions.
Use a pin spanner ( ) to adjust the rear 1
shock spring pre-load.
Position 1: for a light load and smooth
road conditions.
Position 2: standard position.
Positions 3 to 5: for when the motorcycle
is more heavily loaded. (Also increase
spring pre-load for stiffer rear suspension.)
112
Servicing Your Honda
Make sure that both shock absorbers are
adjusted to the same position.
Always adjust the shock absorber position
in sequence (1-2-3-4-5 or 5-4-3-2-1).
Attempting to adjust directly from 1 to 5
or 5 to 1 may damage the shock absorber.