INSPECTION
PISTONS AND PISTON PINS
1.

Check each piston for scuffing, scoring, wear and other defects. Replace any piston that is defective.

2.

Check each piston ring for breakage, damage and abnormal wear. Replace the defective rings. When the piston requires replacement, its rings shouldalso be replaced.

3.

Check that the piston pin fits in the piston pin hole. Replace any piston and pin assembly that is defective. The piston pin must be pressed smoothlyby hand into the pin hole (at room temperature).

PISTON RINGS
1.

Measure the piston ring side clearance. If the measured value exceeds the service limit, insert a new ring in the ring groove to measure the side clearance. If the clearance still exceeds the service limit, replace the piston and rings together. If it is less than the service limit, replace only thepiston rings.

Piston ring side clearance

No.1 : 0.04 - 0.08 mm (0.0016 - 0.0031 in.)

No.2 : 0.02 - 0.06 mm (0.0008 - 0.0024 in.)

2.

To measure the piston ring end gap, insert a piston ring into the cylinder bore. Position the ring at right angles to the cylinder wall by gently pressing it down with a piston. Measure the gap with a feeler gauge. If the gap exceedsthe service limit, replace the piston ring.

Piston ring end gap

Standard dimensions

No.1 : 0.30 - 0.45 mm (0.012 - 0.018 in.)

No.2 : 0.45 - 0.60 mm (0.018 - 0.024 in.)

Oil ring side rail : 0.2-0.7 mm (0.0079 - 0.0276 in.)

Piston ring service size and mark

Standard

None

0.25 mm (0.010 in.) O.S

0.50 mm (0.020 in.) O.S

0.75 mm (0.030 in.) O.S

1.00 mm (0.040 in.) O.S

25

50

75

100

note

The mark can be found on the upper side of the ring next to the end.

CONNECTING RODS
1.

When the connecting rod cap is installed, make sure that the cylinder numbers, marked on rod end cap at disassembly, match. When a new connecting rod is installed, make sure that the notches holding the bearing in placeare on the same side.

2.

Replace the connecting rod if it is damaged at either end of the thrust faces. If it has a stratified wear, or if the surface of the inside diameterof the small end is severely rough, replace the rod.

Яндекс.Метрика