New to me XR650R, first time adjusting valves. First I notice there is no play at all at TDCC. A closer look reveals why. It appears that both intake valve tappets are somehow misaligned, tight, and there is no gap to adjust. Was told by PO that a "Stage One" hot cam had been installed previously. Does this look right? Anyone tell me what is going on here? I've turned the engine over many times making sure I'm at TDC compression. Bike started OK and ran strong last fall. Help!

The intake valves have worn into the seats (Honda's intake valves are soft) reducing the clearance to zero, go ahead and adjust them to the proper clearance. If the intake valves start to need frequent adjustment, it is time to pull the head and install new valves.

You'll find that the lash adjuster is domed on the bottom. It's not supposed to be concentric with the valve stem when the valve is closed. The rocker rotates about the shaft axis so the tip travels in an arc and sweeps across the valve tip as a result. To keep sliding friction and lateral forces to a minimum, the goal is to have it centered at mid-lift, not on the cam's base circle.

Yippee Ki-Yay, on 22 April 2012 - 05:45 PM, said:

My 2000 Xr650r has done more than 50,000km and i have just done my first valve ajustment. My bike was reving up as the engine got warm and would not idle correctly, i think your bike was also doing this?
When you do the ajustment you will be amazed at the power and throtle response. Good luck

Yes, idle would increase as engine got warm, constantly adjusting. Haven't gotten it started yet this year but I think I've got the values right.