I bought my 1997 FX501E new and had it a while before I made it street legal, including an ATK speedo with non resettable odometer. At 4000 miles on the odo, est. 5k including non odo use, I rebuilt the cyl. head and replaced the pin bushing. I also doweled the cyl. to the cases and the head to the cyl. I rode and raced the bike a lot more before I sold it; The current owner reports over 10,000 miles on the speedo and a lot more with a busted speedo cable and still no problems. He does say that it's unfresh now and could use some work but still runs fine. Ran good when I took it apart originally too. Figure about 13,000 miles and never quit running.
I wonder how many people with CRF's can say that?