my exup valve had been broken for a few years. One of the bolts for the cover had snapped and i couldn't drill it out. So with two bolts holding on the cover / housing it didn't go on flush so pinched the valve off centre and jammed it.
Anyway, end result was the valve wouldn't rotate so i just removed it. I took the exhaust off to paint the engine and tidy up the bike as i've done 30,000 miles now. With the bolt removed and a helicoil fitted at a local engineering shop i could refit the valve.
The result - OMFG
[size=78%]- [/size]
i could not believe the effect, it was like a new engine was fitted. I thought there would be a minor improvement and had forgotten what the bike was like with the exup working. I'd always keep a *working* valve - also i've been Ivanised (by the Mike incidentally)
[ although i will be posting a question about valve operation as it doesn't seem to be resetting to the fully closed position - but the performance is night and day ]