Start by taking off the valve
Rocker Arm and push rod then the Spark Plug before fixing the valve guide seal and replacing the valve stem oil seal and valve spring. To avoid dropping the valve into the cylinder space you must set the engine rotation to stop the
Piston at its highest point tdc. Connect the Spark Plug port adapter at j 23590 to the Spark Plug port and roll out compressed air to keep the valves shut. Place the valve spring compressor tool j 38606 onto the valve spring to extract the valve keys alongside the valve spring, spring cap and valve stem oil seal. Check the valve spring condition then replace it on detection of damage. Use the valve seal installer (J 42863) to position the valve stem oil seal onto the valve stem. While controlling the operation, make sure the valve spring seats correctly against the valve guide. Repeat with the valve spring compressor (J 38606) to put the valve spring in place along with its cap and validate the valve keys. After this let go of the valve spring to position the keys correctly and take off the valve spring compressor (J 38606). Disconnect the compressed air system then extract the Spark Plug port adapter part j 23590 before replacing the plug and set-up.