Inspection Of Engine Parts - TOHATSU TLDI MD 115A SERIES Service Manual

Power Unit

17) Inspection of Engine Parts

1. Inspection of Cylinder
1) Measure cylinder inner diameters (D
If any of the diameter is over the limit, replace the cylinder or
bore the liner to make it compatible with an oversize piston.
Cylinder Inner Diameters (D
88.02 mm (3.4654 in)
Oversize Piston :
88.52 mm (3.4850 in)
Functional Limit :
88.08 mm (3.4677 in)
Oversize Piston :
88.56 mm (3.4866 in)
· Measure at the area of the largest wear.
The measurement heights b and c represent
location 5 mm above and below exhaust port.
d represents diameter in crank shaft direction,
e represents the one in crank web direction.
· Replace the cylinder in any of the following
cases; the piston sliding surface is severely
damaged such as deeply scratched or scuffed
so that it cannot be repaired with water-proof
sand paper of #400 - 600, or the difference of
liner inner diameter between the largest worn
area and minimum worn area is 0.06mm
(0.0024 in) or over.
2) Calculate taper of inner diameter of the cylinder.
Replace the cylinder or use oversized piston if the taper
is equal to or over the specified value.
Calculation of taper :
(Measurement Point) a
D -D
1 5
(Measurement Point) c
D -D
2 6
Functional Limit of taper :
0.08 mm (0.0032 in)
3) Calculate out-of-roundness of inner diameter of the cylinder.
Replace the cylinder or use oversized piston if the out-of-
roundness is equal to or over the specified value.
Calculation of out-of-roundness :
Maximum of the following value
(D -D
2 1
(D -D
4 3
(D -D
6 5
Functional Limit of out-of-roundness :
0.05 mm (0.0020 in)
5-38
) at a, b and c.
- D
1 6
- D ) : Standard Value
1 6
)
)
)
D2
D4
D6
a 10mm (0.39 in)
b 30mm (1.18 in)
c 80mm (3.15 in)
D2
D4
D6
a 10mm (0.39 in)
b 30mm (1.18 in)
c 80mm (3.15 in)
D1
a
b
D3
c
D5
d
e
d Crank Shaft Direction
e Crank Web Direction
D1
a
b
D3
c
D5
d
e
d Crank Shaft Direction
e Crank Web Direction
TLDI 115A 2007