I am pretty sure that you're aware that 125cc MXs are not the most effective woods bikes. One thign you can do, though, is to move the compression clicks almost all the way out, place the rebound almost all the way in, for both the shock and forks. Set the race sag in 120 mm. This is to begin with...
If you think the suspension is not delivering any, try to lower the oil in the forks a bit, and release shock preload.
I would save the money of revalving the suspension at this time, since you're not racing or something. After you readquire your skills, then you look for more...