I finally isolated where the noise is coming from on my AT this morning. It's coming from the nearside of the top end of the front cylinder, and the sound is a rhythmic knock. I'm assuming I have lateral play on the cam, though I haven't yet tried the trick where you listen to see if the sound changes when the bike is leant one way or the other. I was wondering how common this is in ATs - who else has had this experience? If you've had it and it turned out to be something less serious than the cam you could cheer me up. Not being of the sunniest dispostion this morning I doubt anyone will though.
The cam runs directly in the head, so unless I get phosphor bronze inserts put in I'll have to source second hand heads and cams. The inserts route and the replacement heads will both be expensive and will mean the bike being off the road while I still need it. I'm thinking this expense and hassle on an engine and gearbox that has done 81,000 miles might not be so wise. Does anyone know of a low-ish mileage (i.e., 50,000 or less) complete engine for sale? An engine swap might be the quickest and, in the long run, cheapest solution.
And no, I don't want to put a Fireblade or Firestorm engine in. If anyone has used a 600 or 650 Transalp I'd be interested to hear what problems there were though.
Stig (AKA Marvin the paranoid ATdroid).