[JAR0023]

.0025 for the go and .003 for the no-go.

I"m collecting tools and parts for my first valve adjust. I want to try both front side and back side methods.

You can buy Starrett 1/2" wide by 12" long feeler guages from Amazon (w/ Prime) for about $2 each. I did not see that our host carries them. -J


ETA - Cut and Paste from Pelican tech article.

Why do we use a .0025" feeler?

Simple math. The ratio of the rocker as it sits against the base circle of the cam is 1.4 to1.

This means the .004" gap at the rocker swivel foot and valve stem is 1.4 times greater than the gap at the point where the other end of the rocker contacts the base circle of the cam.

So if we divide .004" by 1.4 we get .00286". Actually .00285714286",

So .00286" is a rounded off number. Plenty close for what we are doing.

To answer the question why a .0025" feeler?

Since it is smaller than .00286" it will slip easily into the rocker/cam gap.

We now have a GO gauge, .0025".

As a Go gauge it will slip into the rocker/cam gap unless the gap at the other end of the rocker is less than .0035".

Now the NO-GO gauge .003". This should not slip into a properly set gap.