Yamaha F400A 2022 - Disassembling the Cylinder Block; Checking the Piston Diameter

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Cylinder block
Disassembling the cylinder block
1. Remove:
•Flange “1”
TIP:
Install the special service tool “2” to the flange
“1”, secure the tool using a wrench, and then
remove the flange bolts “3”.
2. Remove:
• Connecting rod assemblies
a. Remove the connecting rod caps “1”,
and then remove the crankshaft pin
bearings “2” and connecting rods
(along with the piston) “3”.
TIP:
• To prevent mixing the piston, connecting rod
assemblies “3”, and connecting rod caps
“1”, mark each with an identification number
“a” of the corresponding cylinder.
• Make sure to keep the crankshaft pin bear-
ings in the order of removal.
3. Remove:
• Crankshaft journal bearings (crankcase
side) “1”
•Crankshaft “2”
• Crankshaft journal bearings (cylinder
block side) “3”
TIP:
Make sure to keep the crankshaft journal bear-
ings in the order of removal.
Checking the piston diameter
1. Measure:
• Piston diameter “a”
(at the specified measuring point “b”)
Out of specification → Replace.
Shaft holder “2”
90890-06949
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