Stiffening the suspension?

[Tev62]

The shock adjustments are preload only, no amount of adjusting will affect the softness or hardness of your ride and it won't stop them bouncing around. At your weight it would be reasonable to add one extra notch on the rear preload but you could also experiment with an extra two as long as you can achieve some sag sitting on the bike. After adjusting the rear try leaving the front forks at stock preload and see how the bike handles, the steering will feel a little quicker now you have raised the rear. Wind off the front preload (anticlockwise) if you would like to make the steering a bit quicker again. If your bike is bouncing around at the rear it is more likely that the damping element of your shocks are shot though and they just need replacing.