The valve cover gasket on a Harley-Davidson Evo Blockhead engine is traditionally called the rocker cover gasket. However, the gasket works the same way a valve cover gasket works on an automobile, acting as a seal between the rocker cover and the rocker box. The valves are inside the rocker box. If the gasket leaks, oil will leak through the seal and the engine will lose compression.
1. Remove the four bolts that secure the rocker cover onto the rocker box using a 12-point socket and ratchet. On some models, the rocker boxes may have Allen head bolts. If your Evo engine has them, use an Allen wrench.
2. Pull the rocker cover off the rocker box.
3. Pull the metal gasket off the rocker box and wipe the mating surface of the rocker cover and the rocker box with a clean rag.
4. Place the new metal gasket onto the rocker box and line up the holes for the bolts.
5. Place the rocker cover onto the rocker box and secure it using the four bolts, 12-point socket and ratchet.
6. Duplicate the process on the second cylinder if the rocker gasket leaks on that cylinder.