I just posted this as a response to another thread but thought it worth posting on it's own.
Copy/pasted
I have from day one set the lash to "0.0" on a HOT engine. When you check that cold the readings are all over the place, and never the same on any engine. One valve will read .003" the other .001. A different engine might read ..002", and .005".
I also have a peeve for ticking valves, and the only way I could ever solve it was "0.0" hot. Just set the adjuster to touch the stem, and lock it down. What this whole deal proves out is these are simple , roughly built engines, and the "spec" is a safety margin, and nothing more.
Try it yourself. The bike most likely will have never run better.