I started to do that once. I had one lifter the Literly shot out 1/2 qt of oil before I could adjust the first one. Just one was a steady stream of oil going all over the place. I have adjusted valves a long time ago with my dad and I don't remember any oil coming out that much. I don't have an extra set of valve covers, these have the bolts in the center. I tried putting some card board there try to keep the oil where it needed to be and it just got it everywhere. All over the windshied and the complete opisite side of the motor. And only one is like this. the others that had oil coming out, was just right except for the few with no oil. So I guess I am just going to make a big mess.