I am about to do a valve adjustment, the spec on the hood calls for .18-.22mm
and .23-.27mm. which end would be quiter or should i just stick with .2mm and .25mm. Thanks

 

If you can hit a .04 mm range with the precision it takes to hit one end or the other, more power to ya. The valve adjustment is a feel thing. They give you that range because feeler gauges dont come in increments that small.