Cylinder Wear Inspection
Since there is a difference in cylinder wear in different di-
rections, take a side-to-side and a front-to-back measure-
ment at each of the two locations (total of four measure-
ments) as shown.
If any of the cylinder inside diameter measurements ex-
ceeds the service limit, replace the cylinder.
10 mm (0.39 in.) [A]
60 mm (2.36 in.) [B]
Cylinder Inside Diameter
76.994 ∼ 77.006 mm (3.0313 ∼ 3.0317 in.)
Service Limit: 77.09 mm (3.035 in.)
Piston Wear Inspection
Measure the outside diameter [A] of each piston 11 mm
(0.43 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is under service limit, replace the pis-
76.974 ∼ 76.984 mm (3.0305 ∼ 3.0309 in.)
Service Limit: 76.82 mm (3.024 in.)
Piston Ring, Piston Ring Groove Wear Inspection
Check for uneven groove wear by inspecting the ring seat-
The rings should fit perfectly parallel to groove surfaces.
If not, replace the piston and all the piston rings.
With the piston rings in their grooves, make several mea-
surements with a thickness gauge [A] to determine piston
Piston Ring/Groove Clearance
Piston Ring Groove Width Inspection
Measure the piston ring groove width.
Use a vernier caliper at several points around the piston.
Piston Ring Groove Width
If the width of any of the two grooves are wider than the
service limit at any point, replace the piston.
0.03 ∼ 0.07 mm (0.0012 ∼ 0.0028 in.)
0.02 ∼ 0.06 mm (0.0008 ∼ 0.0024 in.)
0.17 mm (0.0067 in.)
0.16 mm (0.0063 in.)
0.82 ∼ 0.84 mm (0.0323 ∼ 0.0331 in.)
0.81 ∼ 0.83 mm (0.0319 ∼ 0.0327 in.)
0.92 mm (0.0362 in.)
0.91 mm (0.0358 in.)
ENGINE TOP END 5-41