Кто в английском хорошо разбирается пожалуйста попробуйте перевести. Тут про настройку клапанов:
Stihl makes a special tool to adjust them with. If you don't have one you will have to grind down a typical feeler gauge. This is because it needs to fit in between 2 lips on the end of the rocker arms to get to the valve. Use a 3 or 4 thou feeler guage if you don't have the Stihl special tool. Simply move piston to TDC + 5 degrees to clear the compression release. Then place the guage between the rocker and the valve and tighten the rocker nut (8mm) untill the guage is tight but not opening the valve.
The jam nut on the rocker post doubles as adjustment nut. Turn it clockwise to tighten clearance. They run best when set at minimum clearance of .002". I don't recall the maximum clearance in the specs but they run with poor power unless you adjust it down to the minimum.
Here's the deal, you have to alter an absolutely good feeler gauge to work. There is a channel in the rocker that does not allow a regular width feeler to enter between rocker and valve. You need to cut it down to a flip off finger about 1/8" wide to fit. Bring piston to TDC between exhaust and intake strokes.