Cylinder and Piston
Piston Ring/Ring Groove Clearance 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/Ring Groove Clearance
0.040 ∼ 0.080 mm (0.0016 ∼ 0.0032 in.)
0.18 mm (0.0071 in.)
If the piston ring groove clearance is greater than the ser-
vice limit, measure the ring thickness and groove width as
follows to decide whether to replace the rings, the piston
Piston Ring Groove Width Inspection
Measure the groove width at several points around the
piston with a vernier caliper.
Piston Ring Groove Width
If any of the groove widths exceeds the service limit, re-
place the piston.
Piston Ring Thickness Inspection
Measure the thickness at several points around the ring
with a micrometer.
Piston Ring Thickness
If any of the measurements is less than the service limit,
replace all the rings.
When using new rings in a used piston, check for un-
even groove wear. The rings should fit perfectly parallel
to the groove sides. If not, replace the piston.
0.83 ∼ 0.85 mm (0.033 ∼ 0.034 in.)
0.93 mm (0.037 in.)
0.77 ∼ 0.79 mm (0.030 ∼ 0.031 in.)
0.70 mm (0.028 in.)
ENGINE TOP END 5-37