I just bought a 2000 XR650L for $2150. Large tank, White brothers E series exhaust, stiffer springs in the front and rear, lowering link, new tires, K&N air filter. The guy I bought it from said that since it was burning oil he replaced the piston and bored it 0.10 over - a shop did the job. Well - its still burning oil and is very difficult to start after it sits for awhile. When it finally does fire up - a lot of blue smoke. It eventually gets better the more it runs. The bike has 12,000 miles on it and it's my guess that the valve guides are worn and it probably needs a valve job. Thought I would get some opinions from you guys before I rip the head off. Could it be something else? Or should I just unload it and buy a newer one? Thanks for your thoughts.