TOHATSU BFT115A Service Manual page 481

CYLINDER SLEEVE I.D.
Check the cylinder sleeve inner surface for damage
(scores, scratches, etc.).
Measure and record the cylinder I.D. at three levels in
both X and Y axis. Take the maximum reading to
determine the cylinder wear.
Note the identification codes (1) as shown.
IDENTIFICATION CODE: A or I
STANDARD:
87.010 – 87.020 mm (3.4256 – 3.4260 in)
SERVICE LIMIT:
87.070 mm (3.4279 in)
IDENTIFICATION CODE: B or II
STANDARD:
87.000 – 87.010 mm (3.4252 – 3.4256 in)
SERVICE LIMIT:
87.070 mm (3.4279 in)
DIFFERENCE BETWEEN UPPER AND
LOWER PARTS OF SLEEVE I.D.
Measure and record the cylinder I.D. at three levels in
both X and Y axis. Calculate the difference between
upper and lower parts of sleeve I.D.
SERVICE LIMIT:
0.05 mm (0.002 in)
PISTON-TO-CYLINDER CLEARANCE
Subtract each piston skirt O.D. from the corresponding
cylinder sleeve I.D.
STANDARD:
0.020 – 0.040 mm (0.0008 – 0.0016 in)
SERVICE LIMIT:
0.050 mm (0.002 in)
Replace the cylinder block if the measurement exceeds
the service limit (page 15-15).
PISTON RING THICKNESS
Check the piston ring and oil ring for damage.
Always replace the oil ring spacer and side rails as a
set.
Measure the piston ring thickness.
STANDARD:
TOP 1.175 – 1.190 mm
(0.0463 – 0.0469 in)
SECOND 1.175 – 1.190 mm
(0.0463 – 0.0469 in)
CYLINDER BLOCK
Y
X
No.1 CYLINDER
No.2 CYLINDER
No.3 CYLINDER
Y
(1)
No.4 CYLINDER
X
TOP
MIDDLE
BOTTOM
15-33