I had 1 rocker that was really making noise,So i opened her up and tightened her down some.The engine seems to be running rougher now.Did i tighten it down to much.Will that make the enging run rough.Faceing the engine,Left side,2nd cilinder back,2nd rocker,or 4th rocker from the front.Any help plz

Yes, you can tighten it down too much. You need to back the nut off till there is clearance between the rocker and valve. SLOWLY tighten till clearance dissapears, then turn 1/2 turn more.