Yamaha F40BED, Service Manual

Page: 266 / 537

POWR
5-49
CRANKSHAFT AND PISTON
E
INSTALLING THE PISTON RING
CAUTION:
• Do not scratch the piston nor break the
piston rings.
• After installing the piston rings, check
that they move smoothly.
Install:
• Oil ring
• 2nd ring
• Top ring
NOTE:
• Offset the piston-ring end gaps as shown.
• Piston rings should be replaced as a
set.
INSTALLING IN THE ENGINE
CAUTION:
• Check that the upper oil ring gap is
positioned with its locating pin and
then install the piston assembly.
• Install the piston with the "UP" mark
on the piston crown facing towards the
flywheel side.
Install:
• Piston
INSTALLING THE OIL SEAL
Install:
• Oil seal
• Oil seal
CAUTION:
• Do not install the oil seals after tighten-
ing the crankcase bolts or the seal may
be damaged.
• To prevent the inclined seal installation,
install the seals, crankshaft and crank-
case, finger tighten the bolts then
lightly knock the seals.
UP
Piston slider
YU-33294/90890-06529
1
2
1
2