Yamaha F150A, Service Manual

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7-75
Crankcase
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A
Assembling the cylinder block
1. Install a new collar “1” by striking it using
a plastic hammer.
2. Assemble the piston “1”, the connecting
rod “2”, the piston pin “3”, and new clips
“4”.
TIP:
• Face the mark “a” on the connecting rod “2”
in the same direction as the mark “b” on the
piston crown.
• Do not align the clip “4” end with the groove
“c” in the piston pin boss.
3. Install the oil rings “1”, 2nd ring “2”, and
top ring “3”.
Do not scratch the pistons or break the
piston rings.
4. Offset the piston ring end gaps.
TIP:
• Make sure that the “2R” mark “a” on the
2nd ring “2” and “R” mark “b” on the top ring
“1” are facing up.
• Make sure that the piston rings move
smoothly.
5. Install the crankpin bearings “1” into the
connecting rod “2” and connecting rod
cap “3”.
TIP:
Install the crankpin bearings in the original
positions.
6. Apply engine oil to the side of the piston,
piston rings, and cylinder wall, and then
install the piston so that the mark “a” on
the piston crown is facing toward the fly-
wheel magnet end of the crankshaft.
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c b
#3
#4
#5
#1
#2
#3
#4
#5
#1
#2
45˚ 45˚
a
b
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