Also Big D... Called Forge up today, very helpful bloke, but he said it seemed very odd even with the 'smaller' piston it should still work ok and that's the design for it to connect to the pipe rather than a hose type like yours.
Anyway they're going to send me the next stronger and weaker springs to what is in there already to try. His guess was to use a slightly softer 'idle spring'?, the smaller one and see how that goes. But then just to have a play witht he other springs to see if we can get it working ok.
They're getting the springs delivered on Wednesday so he'll send them straight out to me... So friday evening could be busy Lol