Yamaha SR125 1997, Service Manual

Page: 105 / 243

4-25
CYLINDER AND PISTON
ENG
New
NOTE:
New
NOTE:
Engine oil
New
NOTE:
2. Install:
Piston 1
Piston pin 2
Piston pin clip 3
Apply engine oil onto the piston pins.
The “ ” mark
a
on the piston must face the
exhaust side of the cylinder.
Before installing the piston pin clip, cover the
crankcase opening with a clean rag to prevent
the piston pin clip from falling into the crank-
case.
Make sure to install each piston in its respec-
tive cylinder.
3. Install:
Gasket (cylinder)
Dowel pins
4. Position:
Piston rings
Offset the piston ring end gaps as shown.
a Top ring end
b Oil ring end (lower)
c Oil ring end (upper)
d 2nd ring end
5. Lubricate:
Piston outer surface
Piston ring
Cylinder inner surface
6. Install:
Gasket (cylinder) 1
Cylinder 2
Install the cylinder with one hand while com-
pressing the piston rings with the other hand.
Pass the timing chain and timing chain guide
(exhaust side) through the timing chain cavity.