Piston Check; Piston And Piston Ring Check - Mazda 626 MX-6 Workshop Manual

Piston
1. Inspect the outer circumferences of all pistons for
seizure or scoring. Replace if necessary.
2. Measure the outer diameter of each piston at a right
angle (90°) to the piston pin, 18 mm (0.709 in)
below the oil ring land lower edge.
Piston diameter
Size
Standard
0.25 (0.010) oversize 86.194-86.214 (3.3935-3.3942)
0.50 (0.020) oversize 86.444-86.464 (3.4033—3.4041)
79G01C-073
3. Check the piston to cylinder clearance.
Clearance:
0.036—0.075 mm (0.0014—0.0030 in)
Maximum: 0.15 mm (0.0059 in)
4. If the clearance exceeds the maximum, replace the
piston or rebore the cylinders to fit oversize pistons.
Note
If the piston is replaced, replace the piston
rings also.
Piston and Piston Ring
1. Measure the piston ring to ring land clearance
around the entire circumference using a new pis­
ton ring.
Clearance (Top and Second):
0.03—0.07 mm (0.001—0.003 in)
Maximum: 0.15 mm (0.006 in)
2. If the clearance exceeds the maximum, replace the
piston.
69G01A-125
3. Inspect the piston rings for damage, abnormal
wear, or breakage. Replace if necessary.
4. Insert the piston ring into the cylinder by hand and
push it to the bottom of the ring travel in using the
piston.
86U01X-104
INSPECTION AND REPAIR
Diameter
8 5 .9 4 4 — 85.964 (3.38 36— 3.3844)
1
mm (in)
1-51