Originally Posted by
tdr170
The piston to top of cylinder is 3.33mm and the button was 3.14 to equal a .19 clearance so I will need a .31 shim to be at .5.
As you can see the button on my Picco is 3.33 not the .4-.6 you descibed not sure why.
I didn't say that.
I said exactly what you came up with, the difference after measuring the piston to top of liner, minus the headbutton depth should be around 0.2mm, you measured 0.19.....
So yes,adding 0.3mm of headshims, is what you should need te do....