Rear shocks

[Scooterlam]

When getting MOT'd just before Euro I noticed my faithful escort was really soft and I didn't fancy using it fully loaded. I had a look through other shocks and fitted a Readspeed adjustable but it appears the damper has gone on that. next up is a Bitibu again the damper isn't working on that, this one seems to be an air damper and when I pressed the valve a little pressure was released so I guess the seals are still good. I've pumped it up to 2 Bar but have no idea how much pressure it should take.
14 stone rider plus gear.
any ideas ?