[Closed] KS 900i dropper post problems

I'm finally losing patience with my Ks dropper, which is tempermental to say the least. Regularly strip it down, regrease, lube and change the cable...works fine in the house, but as soon as I'm on the trail it just gives up on me. The Cable tension is clearly one of the problems, but the other issue is it seems to reach max exension at a geriatric pace, and any mud/dirt at all means it tops out a good 3 inches short of where it should.

So the next step is to try to increase the air pressure, but last time I had it apart there didn't appear to be any valve? Is this part user servicable, or is it a case of sending it back to those splendid folks at superstar and awaiting their legendary customer service to work its magic?