suspension set up help please

[Falcon 269]

I'm around 18 stone and do alot of spirited riding even loaded up ...

Set shock preload to max, compression damping to max and rebound 3 clicks out, as Nickodemon said.  That's the shock as good as you'll get it.

Forks - 2 rings preload showing, maybe one even.  Compression adjusters 6 - 8 clicks out.  Rebound 3 clicks out.

These are the best you'll get with stock springs. 

What you should really set is your eyes and wallet on springs that are suited to your weight and riding style.