TOHATSU BFT115A Service Manual page 471

Install the piston rings in the ring grooves of the piston
(1) with the marks on the top ring (2) and second ring
(3) facing up.
• Clean the ring grooves thoroughly before installing
the piston rings.
• Install the piston rings with care not to break the
piston rings. Take care not to score or scratch the
piston.
• Do not confuse the top ring and the second ring. The
top ring is glossy while the second ring can be
identified by its dark color.
Install the side rail (top side) (4) by aligning the lug (5)
of the side rail (top side) with the positioning groove (6)
in the ring groove.
• To install the oil rings (7), install the spacer (8) first,
then install the side rail (skirt side) (9).
• Be sure that the lug of the side rail (top side) sits in
the positioning groove securely.
After installing the piston rings, check for smooth
movement of each ring. (except top side rail)
CYLINDER BLOCK
(1)
(8)
(6)
DIMENSIONS OF PISTON RING
B
A
(2)
(3)
(4)
(7)
(9)
(5)
(4)
TOP RING
A: 3.1 mm (0.12 in)
B: 1.2 mm (0.05 in)
SECOND RING
A: 3.4 mm (0.13 in)
B: 1.2 mm (0.05 in)
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