2001-2005 Honda TRX250EX Sportrax TRX250EX Factory Service Manual, Page 92Get this manual
CYLINDER HEADVALVE Remove the timing hole cap from the left side of the rear crankcase cover
Rotate the crankshaft counterclockwise and align the "T" mark on the flywhee with the index mark in the rear crankcase cover
Remove the valve adjusting hole caps from the cylinder head coverMake sure that the piston is atTDC (Top Dead Center) on the compression strokeThe rocker arms should be loeseIf the rocker arms are tight, turn the crankshaft counterclockwise one full turn and realign theTmark with the index markNOTE: When the cylinder head cover is ready to disassembled, loosen the rocker arm shaft retaining