125's were designed to race with a 65 kg pilot.
You should install stiffer springs front and back.
New seals, oil, spring and PD valves should right the front of your ship.
The rear will need similar treatment except the PD valves, but most of the time you are better off buying new shocks. A new pair of springs alown can set you back $200.00. and a service fee from a shock rebuilder will be about $100.00 per shock.
Ji