5-28 ENGINE TOP END

Cylinder, Pistons

Cylinder• Removal

Remove:

Cylinder Head (see Cylinder Head Removal)

• Water Hose [A]

Remove the cylinder [B].

Cylinder Installation

NOTE

○If a new cylinder is used, use new piston ring.

•Install the dowel pins [A] and new cylinder gasket [B].

•Apply engine oil to the cylinder bore.

•The piston ring openings must be positioned as shown in the figure. The openings of the oil ring steel rails must be about 30 – 40° of angle from the opening of the top ring. Top Ring [A]

Second Ring [B]

Oil Ring Steel Rails [C]

Oil Ring Expander [D]

Hollow [E]

30 40° [F]

•Position the crankshaft at #2, #3 piston TDC.

•Prepare two auxiliary head bolts with their head cut. ○Install the two cylinder head bolts [A] diagonally in the

•crankcase.

Install the cylinder block [B].

Pistons [C]

○First insert the #2, #3 pistons, and then rotate the crankshaft at 90° angle.

○Insert the piston rings with your thumbs or the thin (–) screwdriver.

Piston• Removal

•Remove the cylinder (see Cylinder Removal).

Place a clean cloth under the pistons and remove the piston pin snap ring [A] from the outside of each piston.

ENGINE TOP END 5-29

Cylinder, Pistons

•Remove the piston pins.

•Special Tool - Piston Pin Puller Assembly: 57001–910 [A]

Remove the pistons.

•Carefully spread the ring opening with your thumbs and then push up on the opposite side of the ring [A] to remove

•it.

Remove the 3-piece oil ring with your thumbs in the same manner.

Piston• Installation

Apply molybdenum disulfide oil solution to the oil ring expander, and install the oil ring expander [A] in the bottom

•piston ring groove so the ends [B] butt together.

Apply molybdenum disulfide oil solution to the oil ring steel rails, and install the oil ring steel rails, one above the expander 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”.

•Do not mix up the top and second ring.

•Install the top ring [A] so that the "1T" mark [B] faces up.

•Installup. the second ring [C] so that the "2T" mark [D] faces

○Apply molybdenum disulfide oil solution to the piston rings.