Important: 

•	Replace pistons, pins, and connecting rods that are damaged or show signs of excessive wear.

•	The piston, pin, and connecting rod are to be serviced as an assembly.

•	Do not wire brush any part of the piston.

•	Measurement of the components should be taken with the components at normal room temperature.

1. Using cleaning solvent, clean the varnish and carbon from the piston and rod assembly.

Caution: Refer to Safety Glasses Caution in the Preface section.

2. Dry the components with compressed air.



3. Clean the piston ring grooves with a suitable ring groove cleaning tool.
4. Clean the oil lubrication holes and slots.



5. Inspect the piston for the following conditions:

•	Cracks in the piston ring lands, the piston skirt, or pin bosses

•	Piston ring grooves for nicks, burrs, or warpage which may cause the piston ring to bind

•	MINOR imperfections may be removed from the piston with a fine file.

•	Eroded areas at the top of the piston (1)

•	Scuffed or damaged skirts (2)

•	Scoring to the piston pin bore (3) or piston pin




6. Insert the edge of the piston ring into the piston ring groove.

Roll the piston ring completely around the piston. If binding is caused by a distorted ring groove, MINOR imperfections may be removed with a fine file. If binding is caused by a distorted piston ring, replace the rings, as required.




7. Measure the piston ring side clearance with a feeler gage. If side clearance is not within specifications, try another piston ring. If the proper ring-to-groove clearance cannot be obtained, replace the piston, pin, and connecting rod assembly. Refer to Engine Mechanical Specifications .

Important: 

•	Do not attempt to file the end of the piston ring to achieve the proper end gap clearance.

•	Measure the piston ring in the cylinder in which it will be used.

1. Place the piston ring into the cylinder bore 6.5 mm (0.25 in) below the top of the ring travel area. Both compression rings should be installed with the piston ring orientation mark facing the top of the cylinder bore.
2. Insert a feeler gage and measure the piston ring end gap. Refer to Engine Mechanical Specifications .

Notice: Do not clean titanium components with chlorinated solvents. Brake parts, and similar cleaning solvents, safety solvents, or refrigerant that contains chlorofluorocarbons (CFCs) should not be used. Using chlorinated solvents to clean titanium components can result in component damage, leading to stress corrosion cracking that may be undetected with normal visual inspection. Acceptable materials for cleaning titanium components include non-chlorinated solvents, alcohol, acetone, and methanol.

Important: 

1. Inspect the connecting rod for the following conditions:

•	Twisting (1)

•	Proper fit of the connecting rod and cap mating surfaces (2)

•	Nicks or gouges in the bearing bore (3)

•	Damage to the bearing locating slots (4)




2. Measure the connecting rod bearing bore for an out-of-round condition. Refer to Engine Mechanical Specifications .



3. Inspect the connecting rod bearings for craters or pockets. Flattened sections on the bearing halves indicate fatigue.



4. Inspect the connecting rod bearings for excessive scoring or discoloration.
5. Inspect the connecting rod bearings for dirt or debris imbedded into the bearing material.



6. Inspect the connecting rod bearings for improper seating, indicated by bright, polished sections of the bearing surface.