Downloaded torque specs from the manual but I didn't see, not unless I'm blind, specs for the lower and upper rear motor mounts... Thanks in advance
I don't know what size bolts you are refering to.
Anyway, here are the torque specs for the CB650 motor mount bolts. I guess it's safe to assume they're the same for the CB550.
8mm bolts ... 2,6 - 3,2 Kg-m
10mm bolts ... 3,0 - 4,0 Kg-m
12mm bolts ... 8,0 -10,0 Kg-m