2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 214Get this manual
CYLINDER HEADVALVE NOTICE Using torch to heat the cylinder head may cause warpageSupport the cylinder head and drive the valve guides out of the cylinder head from the combustion chamber side using the special toolTOOL: Valve guide driver, 5.5 mm After '05; EX: Valve guide driver, 5.0 mm 07742-0010100 07942-MA60000 VALVE GUIDE DRIVER
Remove the guides from the freezerWhile the cylinder head is still heated, drive new valve guides into the cylinder head from the camshaft side until the exposed height is at the specified value (at the mark)TOOL: Valve guide driver, 5.5 mm After '05; EX: Valve guide driver 07742-0010100 07743-0020000 not available in U.S.A
VALVE GUIDE PROJECTION: '04'05; IN: 16.817.2 mm (0.660.68 in) EX: 17.918.3 mm (0.700.72 in) After '05; IN: 16.116.3 mm (0.630.64 in) EX: 17.918.1 mm (0.700.71 in) Let the cylinder head cool to room temperatureTake care not to tilt or lean the reamer in the guide while reamingUse cutting oil on the reamer during this operation