2004 Official factory service manual for Yamaha YFZ450S ATV Quad., Page 175Get this manual
CYLINDER AND PISTON EBS00252
INSTALLING THE PISTON 1Install: piston rings (onto the piston) NOTE: Be sure to install the piston rings so that the manufacturer's marks or numbers are located on the upper side of the rings Lubricate the piston and piston rings liberally with engine oilad
Position: top ring 2nd ring oil ring Offset the piston ring end gaps as shown