Thanks for that, James

Everything else is ok (Unless I have a loom or ECU problem) hopefully not, with the old valve the nut is screwed down a lot further, the new one did worry me slightly as the nut was at the end of the thread so was worried about it coming loose, I think if I adjust it I may 'loctite' the nut back on, is this a good idea?

The lower spring is the one directly under the nut? I can't remember off hand if there is one either side of the piston?

Martin