Yamaha YW125Y_ Utility Trailer User Manual


 
EAS00007
HOW TO USE THIS MANUAL
This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive
explanations of all installation, removal, disassembly, assembly, repair and check procedures are
laid out with the individual steps in sequential order.
1 The manual is divided into chapters. An abbreviation and symbol in the upper right corner of
each page indicate the current chapter.]
Refer to “SYMBOLS”.
2 Each chapter is divided into sections. The current section title is shown at the top of each page,
except in Chapter 3 (“PERIODIC CHECKS AND ADJUSTMENTS”), where the sub-section
title(s) appears.
3 Sub-section titles appear in smaller print than the section title.
4 To help identify parts and clarify procedure steps, there are exploded diagrams at the start of
each removal and disassembly section.
5 Numbers are given in the order of the jobs in the exploded diagram. A circled number indicates
a disassembly step.
6 Symbols indicate parts to be lubricated or replaced.
Refer to “SYMBOLS”.
7 A job instruction chart accompanies the exploded diagram, providing the order of jobs, names of
parts, notes in jobs, etc.
8 Jobs requiring more information (such as special tools and technical data) are described se-
quentially.
5-32
ENG
RemarksOrder Job/Part Q’ty
1
2
3
4
5
6
7
8
EAS00251
CYLINDER AND PISTON
Removing the cylinder and piston
Cylinder head
Timing chain guide (exhaust side)
Cylinder
Dowel pin
Cylinder gasket
Piston pin clip
Piston pin
Piston
Piston ring set
Remove the parts in the order listed.
Refer to “CYLINDER HEAD”.
Refer to “REMOVING THE CYLINDER
AND PISTON” and “INSTALLING THE
PISTON AND CYLINDER”.
For installation, reverse the removal pro-
cedure.
1
1
2
1
2
1
1
1
CYLINDER AND PISTON
5
8
6
5
3
3
4
2
1
7
ENG
5-33
3
2
1
EAS00253
REMOVING THE CYLINDER AND PISTON
1. Remove:
8piston pin clip 1
8piston pin 2
8piston 3
NOTICE
Do not use a hammer to drive the piston pin
out.
TIP
8 Before removing the piston pin clip, cover
the crankcase opening with a clean rag to
prevent the piston pin clip from falling into
the crankcase.
8 Before removing the piston pin, deburr the
piston pin clip’s groove and the piston’s pin
bore area.
8 If both areas are deburred and the piston
pin is still difficult to remove, remove it with
the piston pin puller set 4.
Piston pin puller set
90890-01304 (YU-01304)
CYLINDER AND PISTON
2. Remove:
8top ring
82nd ring
8oil ring
TIP
When removing a piston ring, open the end gap
with your fingers and lift the other side of the
ring over the piston crown.
3
2
4
4
5
7
6 2 1
3
8
Downloaded from www.ScooterTime.net