Maybe answered before but since I purchased an 86 XL600R in excellent condition yesterday to add to my ever growing stable of bikes, I thought I would offer the differences I have noted between the two bikes, now this is not completey objective in that one is a new 05 XR650L with 2,800 miles on it and uncorked and the XL600R has 14,300 miles on it and is also uncorked (as far as I can tell, supertrapp exhaust and good throttle response etc.) Granted the age difference and milage alone make for a stark contrast in a fair comparison, but the XL600R was the predecessor of the XR and the last of the XL line and as such may be compared. (I don't count the NX250/650 series bikes as being in the same league as an XL). So anyway! since I ony had about an hour on each bike yesterday (boy was it fun) here are the main differences I noted, have I mentioned E-start yet? Ease of Starting; the XR650L wins hands down due to e-start. Power delievery (everyone wants to know this) the XL pulls harder down low, other than that they are nearly identical, the additional 50cc in the XR shows a little but it is not breath-taking. Both like to cruise at 55-60 very easily and get there effortlessy, the XL gearing is spaced just a bit closer than the XR. In a flat out drag race, I think it would be a draw. Handling The XL is born to slide - I had two wheel controlable slides going in every turn - a real grinner! it has a an IRC knobby on the back and a cheng shin up front an odd mix but it felt pretty controlable and defintely would let you know that you had reached the break away point. (no I did not crash) Albeit the XL is 21 years old the suspension was still plush, not a MX'er by any means an neither should it be compared ot one, it felt good for a BIG thumper. The XL is easier to ride and is confidence inspiring and lacks the tall "fall over feel" of the XR650L. The XR650L suspension is even better but it feels short and tall and has a nose dive to it from a high CG, the XL lacks the Nose dive tuck in a tight turn that the XR has. Overall: There is no clear cut winner. Both bikes have thier own personaility, the XL600R would be better off with E-start for sure, becuase unless you know the drill to start a BIG thumper, it can be a pain in the arse and is not knee friendly. The XL is lower and handles a bit better, power band is very good and it seems more dirt oriented, the XR has a weird power spread with the stock sprockets 1st is too low and 2nd too high. The XL will wheelie in 2nd on command - not always so with the XR. I paid 1,700 bucks for the XL, it is in great shape and was purchased form the 2nd owner who had done nothing but maintain it, too big in the woods was his complaint, which it is. But it is a very fun bike to ride!