Thanks Dave!

MAtt, Andy if you chaps have seen this coller thing, i would be very greatfull if you chip in with a pic or partnumber. Clutching at straws maybe but something has made the bike go pop so quickly, An old bit of ring maybe but there is clearly a powervolve issue as well!

Here s another, Has anybody modified the powervalve itsself so that it dosnt hit the piston/ring or would this be a bad idea?