1- Valves clearance gets smaller with wear.
2- The higher range but within the specs. Target closer to .41
3- To measure the gap, the cams must be in a specific position where there is no lift. I suggest you get the videos from Jim Van Badden. R1200_Wethead_2013+_DVD (jimvonbaden.com)
Replacing the shims isn't just a matter of removing the cam. You will need a specific tool for the chain tensioner.

 

Check out boxflyer on YouTube. He does the entire maintenance. Also set the clearance on the tight side. Once these break in they do not tend to change again and tight makes for a quiet bike.

 

Boxflyer does 1250. JVB does 1200.

 

In the screw and locknut days of valve adjustment we had this saying, "tappy valves are happy valves".

 

Hi all,

I am doing the yearly maintenance of my 2015 R1200GS and after I measured the gaps of the valves I came to 3 questions...

1 - Do the clearance usually get smaller or larger?
2 - To calculate the thickness of the new shim, do I have to target the higher range of the tolerance or the lowest? (has to do with question #1).
3 - To measure the gaps, the position of the valves has to be a particular one. I assume that to change the shims, the position doesn't matter as long as you assemble the gears right were they were (marking the teeth), is that right?

Regarding the question 2, here is my example.

all my exhaust clearances are out of specs. They are all four around 0.26mm gap, whereas the specs are between 0.34 and 0.41. With the new shims should I target 0.34 or better 0.41?? I guess if the clearances get smaller with the time, it would seem logical to target the latter, right?

Thanks in advance!

With over 100,000 miles on my 2014 GS, the valves have NEVER needed adjusting. Every time within spec.