2006-2012 Honda TRX90 TRX90EX/X Service Manual, Page 114Get this manual
CYLINDER HEADVALVES Install and tighten the cylinder head right side cover boltsInstall and tighten the spark plug to the specified torqueTORQUE: 12 Nm (1 .2 kgfm9Ibfft)
SPARK PLUG
Install the new gasket onto the intake manifold