Has everybody who wants one of these got one now? Only I'm going to get a local firm to knock one out for me, and I may as well get a few done while they're at it..? Price would be about £10 incl postage in the UK.
You can usually tell by the noises the servo unit makes when you switch on the ignition. If it's working normally, you hear the thing whirr as it cycles closed and open again, then it falls silent. If the valve has seized, you may hear it clearly struggling to close, then it gives up and you will hear repeated short sounds (sometimes squeaking noises) for quite some time (or until you start the engine, at least) as it tries to move the valve. You can confirm it by popping the plastic cover off (two Torx screws) and watching the cables/pulley. On my bike, I usually noticed a slight difference in exhaust sound - more of a tendency to pop and spit on a trailing throttle.
I have no immediate plans for another batch - but if there's sufficient interest (and positive feedback from this lot) then I may have some more made up.
Disconnect everything. The ECU will log an error but it has no other effect and will not light the warning triangle.
If anyone in the midlands wants a tube making talk to Andy at Xtreme Stainless (bespoke exhausts). Airfield Industrial Estate, Hixon, Stafford ST18 0PF 01889 270014
Anyone wanting an aftermarket exhaust - anything for a Mk1 or Mk2 will fit - they came without a flappy valve.