Service Manual — page 290 of 715

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5-40 ENGINE TOP END
Cylinder, Pistons
Piston Installation
                              NOTE
    ○If a new piston is used, use new piston ring.
• Apply molybdenum disulfide oil solution to the oil ring ex-
  pander, and install the oil ring expander [A] in the bottom
 piston ring groove so the ends [B] not butt together.
•Apply molybdenum disulfide oil solution to the oil ring steel
 rails, and install the oil ring steel rails, one above the ex-
 pander and one below it.
○Spread the rail with your thumbs, but only enough to fit
 the rail over the piston.
○Release the rail into the bottom piston ring groove.
                              NOTE
    ○The oil ring rails have no “top” or “bottom.”
• Apply
  rings.
         molybdenum disulfide oil solution to the piston

                              NOTE
    ○Do not mix up the top and second ring.
• Install the top ring [A] so that the “1T” mark [B] faces up.
• up.
  Install the second ring [C] so that the “2T” mark [D] faces

• Install the piston with its dent mark facing forward.
• Apply  molybdenum disulfide oil solution to the piston pins
  and piston journals.
• Fit a new piston pin snap ring into the side of the piston
  so that the ring opening [A] does not coincide with the slit
    [B] of the piston pin hole.
○When installing the piston pin snap ring, compress it only
    enough to install it and no more.
                            NOTICE
    Do not reuse snap rings, as removal weakens and
    deforms them. They could fall out and score the
    cylinder wall.

• Install the cylinder (see Cylinder Installation).
Cylinder Wear Inspection
• Since  there is a difference in cylinder wear in different di-
  rections, take a side-to-side and a front-to-back measure-
    ment at each of the two locations (total of four measure-
    ments) as shown.
    If any of the cylinder inside diameter measurements ex-
    ceeds the service limit, replace the cylinder.
      10 mm (0.39 in.) [A]
      60 mm (2.36 in.) [B]
    Cylinder Inside Diameter
      Standard:       76.994 ∼ 77.006 mm (3.0313 ∼ 3.0317 in.)
      Service Limit:   77.09 mm (3.035 in.)