I'm replacing a head gasket on my son's 2000 CR-V. Before putting the cylinder head back on, I had it machined and new valves inserted. Everything went back together fine until ...
I was doing the valve lash adjustment.

On the intake side it worked just fine. But on the exhaust side, even with the rockers adjusted all the way down, I can't get any space at all.

Any ideas?

Here's a bit of additional info: when the machine shop was doing the valve job on the head, they noticed that the existing (old) valves had been manipulated quite a bit - some of the valves were cut pretty thin and others had the tips cut short

 

Assuming your procedure for adjustment is correct.

The valves are either wrong for the head, manufactured incorrectly and too long, or the seats have been cut so far into the head the valves now sit too deep.

Just to be sure, you have the cylinder you are working on at TDC and the exhaust valves are closed. You are off the exhaust lobe. Then you are backing the lash adjustment screw all the way off and never getting clearance?