I have been doing some routine maintenance today like repack the silencer, add a long fuel screw etc. Included in the list was valve clearance check and adjust if needed. One of the inlet valves was slightly out of spec so I removed the tensioner and the cam cover. I was aware of the locating clip in the cam bearing but due to old age or something it went under force of gravity straight down using the cam chain as a guide into the engine. B#####ks! No chance of getting it back through the top so I drained the oil and removed the generator cover. I was shocked to find the lower idler gear outer bearing to be cracked through and in 2 pieces. Up to now there had been no starter issues with this bike and as far as I was aware the casting broke elsewhere on the 2003 models. It looks like it has been like it for a while as there are signs of wear on the face of the back bearing which is the crankcase of course. Here is the pictorial evidence: http://i2.photobucket.com/albums/y30/turwr450/idlerfrontbearing.jpg http://i2.photobucket.com/albums/y30/turwr450/idlerbackbearing.jpg http://i2.photobucket.com/albums/y30/turwr450/idlerfrontbearingpieces.jpg I will now do the 2004 mod as soon as I can get the parts. Does anyone do a complete kit for this mod? It looks like I had a lucky escape here. Has anyone else had this happen in this way?