I'm riding an 03 kfx 400 and I've done the valve lash probably 4 times in it. Now my left side intake valve is down to a 2.50 mm shim and the top surface of the shim sits flush with the valve seat. The problem is I have no valve lash. What am I going to have to do. I don't think installing a smaller shim is an option because the one that is in there is already sitting flush. Am I going to have to Install a new valve? Valve seat, what? If I'm doing one is it worth doing all 4 even though they're no wearing like this one. Any suggestions or guidance would be awesome. Thanks.