FOC-US2K

Ok so heres the story. A couple of days ago I went to adjust my valves on my 00EX, I was getting a slight tap and the dealer said to have them adjusted. They wanted 129 dollors. I did it my self following the hanes manual .007 on the intake side and .009 on the exhaust side. So I get done I warm the car up and it idles rough and cuts off. I check the timming, rechecked the valve's, reset the computer adjusted the IAC. Nothing worked. So I went to the dealer and they said to do .18MM to .22MM on the intake side and .23MM to .27MM on the exhast side. After looking at it for awhile I found out that .007 Inches does not convert to .18MM but actualy .178 and .009 inches is not .23MM its really .229MM. So after redoing the valve clearences 3 times the charm. The tech at the dealer recomended .20MM for the intake and .23 for the exhaust and that worked for me.

I was wondering why making the valve clearence less why does that mess the idle up????? Is it because of the change in valve open duration or how much it opens or what???