2006-2012 Honda TRX90 TRX90EX/X Service Manual, Page 118Get this manual
CYLINDER HEADVALVES Tighten the mm bolt with new sealing washer securely
Adjust the valve clearance (page 3-B) Apply eng ine oil to the valve adj uster hole cap threadsCoat new O-rings with clean engine oil and install them onto the valve adjuster hole capsApply eng ine oil to the valve adjuster hole capsInstall and tighten the valve adjuster hole caps to the specified torque