2004-2009 Honda TRX450R/TRX450ER Service Manual, Page 111Get this manual
LUBRICATION SYSTEM (After '05)
OIL STRAINER
REMOVAL
Remove the balancer shaft (page 16-7)Remove the snap ring from the oil pump driven gear
OIL PUMP DRIVEN GEAR Remove the oil pump driven gear and drive pinOIL PUMP DRIVEN GEAR