Yamaha TT-R125EY, Service Manual

Page: 130 / 258

4-37
ENG
CYLINDER AND PISTON
ASSEMBLY AND INSTALLATION
Piston ring and piston
1. Install:
• Piston rings
(onto the piston)
• Be sure to install the 2nd piston ring so that
the manufacturer’s mark or number are located
on the upper side of the ring.
• Lubricate the piston and piston rings liberally
with engine oil.
2. Position:
• Top ring
• 2nd ring
• Oil ring
Offset the piston ring end gaps as shown.
a
: Top ring end
b
: 2nd ring end
c
: Oil ring end (upper)
d
: Oil ring end (lower)
3. Install:
• Piston
1
• Piston pin
2
• Piston pin clips
3
• Apply engine oil onto the piston pin, piston
rings and piston.
• Be sure that the arrow mark
a
on the piston
points to the exhaust side of the engine.
• Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase.
• When removing the piston pin clip, pop it out
using the small opening
b
.
4. Lubricate:
• Piston
• Piston rings
• Inside of cylinder
Apply a liberal coating of engine oil.
New
TIP
TIP
TIP