Hi guys, As you can see from my signature, I'm usually at other areas of the TT site. But a good friend is wanting to buy a used XR 600 or 650, and asked me to help him. Questions are... Are there problems with these bikes that he should look for when shopping for a used one? Which bike would you recommend? Thanks for you help! And oh yea, do any of you know of a good one for sale? He's in New Mexico.