Piston, Ring, Pin, and Connecting Rod Inspection: Inspection

How to use this service information .

1. Piston Ring End Gap - Inspect

   Preconditions 

   • Piston Rings Removed

   Procedure/Specifications 

   NOTE:

   Before doing this inspection, do the cylinder block and piston inspection procedure first and hone the cylinders, if needed.

   1. Using a piston that has its rings removed, push a new ring (a) into the cylinder bore.

   Measurement Position 

   Standard Value
   b	15-20 mm (0.59-0.79 in)

   Courtesy of HONDA, U.S.A., INC.

   2. Measure the ring end-gap (c) with a feeler gauge.

   Specifications 

   	Object	Standard Value (New)	Service Limit
   c	Top Ring	0.20-0.28 mm (0.0079-0.0110 in)	0.28 mm (0.0110 in)
   	Second Ring	0.29-0.41 mm (0.0114-0.0161 in)	0.41 mm (0.0161 in)
   	Oil Ring	0.10-0.40 mm (0.0039-0.0157 in)	0.40 mm (0.0157 in)

   Result 

   • If the gap is too small, check to see if you have the proper rings for your engine.
   • If the gap is too large, recheck the cylinder bore diameter against the wear limits - Refer to: Cylinder Bore Honing  or Block and Piston Inspection . If the bore is beyond the service limit, the engine block must be rebored.
2. Piston Pin - Inspect

   Preconditions 

   • Piston Pin Removed

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   • Measure the diameter of the piston pin.

   Tool Details 

   Name
   a	Micrometer

   Specifications 

   Object	Standard Value (New)	Service Limit
   Piston Pin	19.960-19.964 mm (0.78583-0.78598 in)	19.957 mm (0.78571 in)

   Result 

   • If the measurement is not within specifications, replace the piston pin.
3. Piston Pin-to-Piston Clearance - Inspect

   Preconditions 

   • Piston Pin Removed
   • Piston Pin Normal Condition

   Figure 1 

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   1. Measure the diameter of the pin.

   2. Zero the dial indicator (a) to the pin diameter. (Figure 1)

   Tool Details (Figure 1) 

   Name
   a	Dial Indicator

   Figure 2 

   Courtesy of HONDA, U.S.A., INC.

   3. Check the difference between the pin diameter and the pin hole diameter in the piston. (Figure 2)

   Specifications 

   Standard Value (New)	Service Limit
   -0.004-0.004 mm (-0.00016-0.00016 in)	0.007 mm (0.00028 in)

   Result 

   • If the measurement is not within specifications, replace the piston .
4. Piston Pin-to-Connecting Rod Clearance - Inspect

   Preconditions 

   • Piston Pin Removed
   • Piston Pin Normal Condition

   Figure 1 

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   1. Measure the diameter of the pin.

   2. Zero the dial indicator (a) to the pin diameter. (Figure 1)

   Tool Details (Figure 1) 

   Name
   a	Dial Indicator

   Figure 2 

   Courtesy of HONDA, U.S.A., INC.

   3. Measure the pin-to-rod clearance. (Figure 2)

   Specifications 

   Standard Value (New)	Service Limit
   0.004-0.016 mm (0.00016-0.00063 in)	0.016 mm (0.00063 in)

   Result 

   • If the measurement is not within specifications, replace the connecting rod .
5. Ring-to-Groove Clearance - Inspect

   Preconditions 

   • Piston/Connecting Rod Assembly Removed (Piston Ring Installed)

   Courtesy of HONDA, U.S.A., INC.

   Procedure/Specifications 

   • After installing a new set of rings, measure the ring-to- groove clearances.

   Tool Details 

   Name
   a	Feeler Gauge

   Specifications 

   Object	Standard Value (New)	Service Limit
   Top Ring	0.060-0.085 mm (0.00236-0.00335 in)	0.110 mm (0.00433 in)
   Second Ring	0.035-0.060 mm (0.00138-0.00236 in)	0.080 mm (0.00315 in)

   Result 

   • If the measurement is not within specifications, replace the piston.