Page of an article I wrote about using a tool designed to perform the "Lycoming rope trick".
This procedure allows a valve to be removed through the top sparkplug hole for inspection 
and cleaning, while the guide is also inspected, and reamed of deposits if necessary.  My
"Snagger tool", inserted through the bottom sparkplug hole, "lassos" the valve and allows
complete control and manipulation.  After the cleaned valve is re-inserted in the guide
(and held securely! with fingers) the Snagger tool is removed and clean, soft cotton braided
rope is fed into the plug hole.   The pison is brought up to compress the rope against the 
valve head to hold it in place so the springs and keepers can be re-installed.  smt