TOHATSU BFT75A - Crankshaft, Piston, Cylinder Block Inspection

15-18
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CYLINDER BLOCK
CRANKSHAFT/PISTON/CYLINDER
BLOCK INSPECTION
PISTON SKIRT O.D.
Check the piston outer surface for damage (scores,
scratches, etc.).
Check the piston for warpage and cracks.
Measure and record the piston O.D. [1] at 13 mm (0.5
in) [2] from the bottom and perpendicular to the piston
pin bore.
If the measurement is less than the service limit,
replace the piston with a new one.
CYLINDER SLEEVE I.D.
Check the inner wall of the cylinder for damage (scores,
scratches, etc.).
Measure and record the cylinder I.D. at three levels in
both X and Y axes.
Take the maximum reading to determine the cylinder
I.D.
If the measurement exceeds the service limit, replace
the cylinder block with a new one.
DIFFERENCE BETWEEN TOP AND
BOTTOM POINTS OF SLEEVE I.D.
Determine the difference of the cylinder sleeve I.D.
between the top and the bottom measurements.
If the measurement exceeds the service limit, replace
the cylinder block with a new one.
PISTON-TO-CYLINDER CLEARANCE
Determine the difference between the piston skirt O.D.
and the cylinder sleeve I.D.
If the measurement exceeds the service limit, replace
the cylinder block with a new one.
STANDARD:
72.98 – 72.99 mm (2.873 – 2.874 in)
SERVICE LIMIT:
72.97 mm (2.873 in)
[2]
90°
[1]
STANDARD:
73.00 – 73.02 mm (2.874 – 2.875 in)
SERVICE LIMIT:
73.07 mm (2.877 in)
SERVICE LIMIT:
0.05 mm (0.002 in)
STANDARD:
0.01 – 0.04 mm (0.0004 – 0.0016 in)
SERVICE LIMIT:
0.05 mm (0.002 in)
Y
X
BOTTOM
MIDDLE
TOP