well, just got back from a noon round there putting a new belt kit on there
cheapest i could find was £45 and it was a GATES! rocked up, stripped it down, got the crank to tdc, belt off and realigned the cams. intake cam had jumped two or three teeth, it was at last 30* out, maybe more.
old tension was proper fubar, might try and get some pics up. put the new belt on, tried to retime it without faffing with the cam pulleys but couldnt get the tension i liked.
did it all properly, put it back together far enough that it could be started. i knew it went round without making contact but who knows the state of the valves
fired it up and could hear all sorts (then remembered one wheel was off, one disc would be spinning) so put my foot on the brakes and all was silent and all was good in the world
friggin thing is good for another 96k.
old tensioner had failed badly, the plastic roller was off the bearing, god knows how it escaped because there didnt look like there was enough space for it to get past the belt and cover.
fixed