I had to replace the tappet screw because it was worn and I couldn't get the allen to bite and when I tried to adjust the valves, the rocker arms has a teflon washer or very thin nylon washer between the rocker arm and casing that the rocker what went through. I ripped the washer no matter how careful I was because it was very old and thin. I looked everywhere on-line for the paper thin teflon washers and couldn't find one anywhere. Is that really needed? And if so, where can I find the set if it is needed?