I have a 2007 wr450f that had the top end done recently, roughly 30 hours ago. I have taken it out a decent amount this year and it has been running great. Went out for a 20 mile ride this last week, and at about mile 10 the bike bogged to a stop. Assumed one of the drain hoses got clogged due to going through some mud causing it to bog and die. Had a little bit of trouble restarting it but got it restarted and was running good again and started heading back at that point, but noticed the valves were clicking unusually loudly. Stopped again checked the oil to make sure that was not the cause of the valve noise, it was good. Got another few miles and noticed oil on my boots and smoking off the header. Stopped again and saw the valve cover moving up and down slightly (like a 1/16”) with the majority of movement at the front of the motor and sputtering oil from between the seal and the valve cover as it would idle. Checked the valve cover bolts they were seated.
Got it home and washed off, topped off with oil since it had splattered a bunch out and tried starting it. The starter would get stuck on one point of the stroke (compression stroke?), and when I kicked it, it felt more difficult than usual at the one spot but would start and idle. It would idle just fine but was still sputtering oil where the valve cover is moving up and down.
Just guessing, but could this be something with the auto decomp since it still starts and idles well?
Edited by neffly4u, October 15, 2012 - 02:50 PM.