valve adjustment

I did my first valve adjustment about 20 hrs ago, and noticed some valve chatter recently when good and hot. So I went back in and adjusted again. The intakes were a little slack.
My questions;
What do they mean by a slight drag on the feeler guage? To slide kind of easy or still slide but with a little effort back and forth?
Is it normal to hear a little valve clicking when motor is good and hot, because I can't hear it when cold or warm?
Thanks for your help,
John

[oynot400]

Here is a tip when trying set valves. With the proper feeler guage in place tighted while sliding the guage back and forth. There will be a point when it will be so tight that it can't be easily moved. From that back off the adjustment screw until it feels like a slight drag on the feeler guage. Once this point is found leave the feeler guage in place and tighten the lock nut and check the valve lash again. Sometimes it will change.
I have not noticed a valve chatter in mine even when it is hot. Just be sure to run a good quality oil and change it on a regular basis.
If you need anything else me know. ;)

if you have your idle set low you can hear the chatter on mine

I changed my oil to mobil 1 tri-synthetic 15w-50, I wonder if this is the reason I hear the valves a little. Maybe I need a 20w-50 synthetic.
Thanks oynot, thats how I did the adjustment, so I should be good.
I met two guys about a month ago who had their 400ex's for two years and never adjusted the valves.
John

[oynot400]

John,
I run 20w-50 synthetic in the summer and 10w-40 synthetic in the winter. I think it is a good idea to check the valve lash every 6 months or so, more often if you hear chattering.