| You dont really change a shim. They are nothing more than round discs that sit between opening and closing rockers and every valve, both inlet and exhaust.
They are made in different thicknesses and are fitted to achieve a valve clearance. A variety of things wearing or not, can affect the clearance, not least of all them not being right from day one!
So you would first measure the clearance you have on each valve. compare that to what the gap should be, then either add a thicker or thinner shim to replace the existing one, to achieve the corrected gap................
Does that help? |