2006-2012 Honda TRX90 TRX90EX/X Service Manual, Page 179Get this manual
CRANKCASEITRANSMISSIONCRANKSHAFT Check the timing sprocket for wear or damageIf you replace the timing sprocket, align the center of the sprocket teeth with the center of woodruff key groove as shown
INSTALLATION
Pourcm of engine oil into the connecting rod big end bearing and crankcase bearingsInstall the crankshaft into the left crankcase, being careful not to interfere the connecting rod with the crankcaseAssemble the crankcase halves (page 11-15)