First, you need to determine the maximum torque loading required by the gear-spocket in operation. Also determine if there will be any loading imparted perpendicular to the sprocket gear that will impart additional axial tension loading on the bolts.
Are you using grade 8 bolts?
Once you know the loading that the bolts need to absorb, then you can compare the current design to loading requirements to see if you need to add or reduce bolt shear capability.
You will need to know bolt pre-load to baseline the fasteners relative to max. (peak) torque requirements of the sprocket.