it might cause it to be loosened and fall out.
what do the insides of the pre cups look like? probably look like *** considering how the heads surface looks
Quote from: "libbybapa"Hand lapping is accomplished by placing a small amount of valve grinding compound between the valve and seat and using a suction cup tool to rotate the valve in the compound. It basically works similar to sandpaper and helps the valves to seal completely.AndrewIts implied that you remove the cam, lifters, and springs prior to lapping. And, yes, lapping is a very very good idea. I would also be a little concerned about the erosion next to the precombustion cup on that first cylinder - looks like it might affect it, maybe not.
Hand lapping is accomplished by placing a small amount of valve grinding compound between the valve and seat and using a suction cup tool to rotate the valve in the compound. It basically works similar to sandpaper and helps the valves to seal completely.Andrew
Just don't put a questionable head on and then start suspecting other things that are wrong when you aren't sure about the head first.