That's because that's when the XTZ660 was made. Try XT660Z. ;)

Or just go here...

http://www.wemoto.com/bikes/yamaha/x...all_balls_usa/

Thanks Uber

Bougt bearings as described in post.

Top end OK

Bottom end minging - could not turn with my fingers.

Will just grease up the top.

Trouble with the bottom though. - How to remove the bearing?
http://www.facebook.com/media/set/?s...3&l=def92e9019

Mine are notchy at 4000km, what I have found when cold it is not to noticeable but when hot feels real bad. Maybe when setting up the preload on the bearing it may be worth setting them on the loose side with no play due to the oil tank in the frame heating up and causing them to tighten up.