Have you managed to get the valve out?
If you can fix the whole set up for 200 quid that would seem to me to be worthwhile.
As others have said, valve stuck open, loss of bottom end torque.
Valve stuck at tick over position, bottom end OK, but loss of top end power.
Valve closed - bike will probably run pretty crappy.
And bear in mind the bike in standard trim already runs on the lean side, a non-functioning EXUP won't help, but my guess is it won't do much harm.
I guess that the servo noise at start up is the valve closing, so it's default is open!
That's a good question. And one I couldn't answer definitely until I carry out my EXUP overhaul again.
But when you turn on the ignition the valve drives to it's zero position, I think that's slightly open.
The valve can close under it's own weight when it is free, but can't remember if it can do that with the cables attached.
Lots of good info here -
www.cartestsoftware.com/fz1/exupmaintenance.htmlIf the screws are tight, soak and keep soaking em in a good quality release oil, continuing to ride the bike will probably help the release oil work, just keep applying every day.
If they have sheared, then you'll have to pop the down pipes off and probably best to hand over to a good engineering works to get them out. Do stress to them that's it's easy to warp the valve. It's should slip out OK once you have removed all the screws.
Replace the screws with stainless items.
Whether you fix it or not just depends on how much you like the bike.
And if it hasn't been ivanised that's worth thinking about too. Never mind the improved performance after ivanisation, the thing is just so much smoother and nicer to ride, so even if you are plodding about ivanisation is well worthwhile.