1999-2002 TRX400EX Fourtrax Service Manual, Page 95Get this manual
CYLINDER HEADVALVE Removethe following:spring retainerinner and outer valve springs -valve -stemsealvalvespring seat NOTE: Mark all parts during disassembly so they can be olaced back in their original locations
SPRINGS
-SPRING SEAT
Remove the carbon deposits from the combustion chamber and clean off the gasket surface, being careful notto damage the gasket and valve seat surfaces