Removal and Replacement

REMOVAL SERVICE POINTS
CONNECTING ROD CAP REMOVAL





(1) Mark the cylinder number on the side of the connecting rod big end for correct reassembly.
(2) Keep the removed connecting rods, caps and bearings in order according to the cylinder number.

INSTALLATION SERVICE POINTS
>A

(1) Set the oil ring spacer in the piston ring groove. Then set the upper side rail. Lastly, set the lower side rail.

NOTE:
(1) The side rails and spacer may be installed in either direction.
(2) New spacers and side rails are colored for identification of their sizes.

(2) A side rail can be easily installed by fitting one end of the side rail in the piston groove and pressing the remaining portion into position by finger as shown.

Caution: Use of ring expander to expand the side rail end gap can break the side rail, unlike other piston rings.

(3) Make sure that the side rails move smoothly in either direction.

>B<PISTON RING NO. 2 AND NO. 1 INSTALLATION

(1) Using piston ring expander, fit No. 2 and then No. 1 piston ring into position.

NOTE:
(1) Note the difference in shape between No. 1 and No. 2 piston rings.
(2) Install piston rings No. 1 and No. 2 with their side having marks facing up (on the piston crown side).

>C>PISTON AND CONNECTING ROD ASSEMBLY INSTALLATION
(1) Liberally coat the circumference of the piston, piston ring and oil ring with engine oil.
(2) Arrange the piston ring and oil ring gaps (side rails and spacer) as shown in the illustration.

(3) Install the piston and connecting rod assembly with the front mark (arrow mark) on the top of the piston facing towards the camshaft sprocket.

(4) While holding the piston rings securely with a suitable piston ring compressor, insert the piston and connecting rod assembly into the cylinder bore.

Caution: Hammering it in with a strong force could cause damage to the piston rings and crankshaft pins.

>D<CONNECTING ROD CAP INSTALLATION

(1) Mate the correct bearing cap with the correct connecting rod by checking with the alignment marks marked during disassembly. If a new connecting rod which has no alignment mark is used, position the notches for locking the bearing on the same side.

(2) Check if the thrust clearance in the connecting rod big end is correct.

Standard value: 0.10 - 0.25 mm (0.0039 - 0.0098 inches)
Limit: 0.4 mm (0.0157 inches)

INSPECTION
PISTON RING

(1) Check the clearance between the piston ring and ring .groove. If the limit is exceeded, replace the ring or piston, or both.

Standard value:
No. 1 0.03 - 0.07 mm (0.0012 - 0.0028 inches)
No. 2 0.02 - 0.06 mm (0.0008 - 0.0024 inches)
Limit: 0.1 mm (0.004 inches)

(2) Insert a piston ring into the cylinder bore. Force it down with a piston, its crown being in contact with the ring, to correctly position it at right angle to the cylinder wall. Then, measure the end gap with a feeler gauge. If the end gap is excessive, replace the piston ring.

Standard value:
No. 1: 0.25 - 0.40 mm (0.0098 - 0.0157 inches)
No. 2: 0.40 - 0.55 mm (0.0157 - 0.0217 inches)
Oil: 0.15 - 0.50 mm (0.0059 - 0.0197 inches)
Limit:
No. 1: 0.8 mm (0.031 inches)
No. 2: 0.8 mm (0.031 inches)
Oil: 1.0 mm (0.039 inches)

CRANKSHAFT PIN OIL CLEARANCE (PLASTIGAGE METHOD)
The crankshaft oil clearance can be measured easily by using a Plastigage, as follows:

(1) Remove oil and grease and any other foreign material from the crankshaft pin and the bearing inner surface.
(2) Install the crankshaft.
(3) Cut the Plastigage to the same length as the width of the bearing and place it on the pin in parallel with its axis.
(4) Gently place the crankshaft bearing cap over it and tighten the bolts to the specified torque.
(5) Remove the bolts and gently remove the crankshaft - bearing cap.
(6) Measure the width of the smashed Plastigage at its widest section by using a scale printed on the Plastigage bag.

Standard value: 0.02 - 0.05 mm (0.0008 - 0.0020 inches)
Limit: 0.1 mm (0.004 inches)