Posted by js on December 16, 2002 at 15:06:57:
In Reply to: Lap posted by Green on December 16, 2002 at 14:55:59:
Merriam-Webster:
"after unscrewing a top valve cap to oil a piston, suddenly barely catching the piston - which was shot out of it's casing like a rocket by an over-tensioned spring - between one's legs, followed by a sigh of relief.
NO ACTUALLY it means to "final fit" (or refit) a piston to its casing using the actual piston and casing as friction surfaces. Some sort of mild abrasive pasty compound is placed between the piston and its casing for this purpose.