Why do B&S have a range for valve adjustments?

[Jonny_The _Grass_Man]

I need to adjust my valves on my B&S engine to hopefully cure some starting issues. I have only adjusted valves on my dirt bikes and it was a set number for setting the rocker/valves. My B&S owners manual says the vales should be set to .004 to .008

Is there a preference to go tighter/looser? Why do they have a range and not a set single number?

 

[ILENGINE]

Because somebodies .006 is somebody elses .004 and vise versa. it is not a exact science nor do they have to be exact. Most techs tend toward the lower to middle end of the adjustment range. So an engine that calls for .004-006 IN and .005-.007 Ex most techs will just set both at .005 and go with it.

 

[T/AChad]

I like to use the step type no go feeler gauges. 004 will go in but a 006. wont.