Yamaha YBR 125 Service Manual page 131

Assembling and adjustment of engine
Piston and piston ring
1. Installation of piston ring
Oily plate
Oil scraping plate
2nd ring
1st ring
Note:
When installing the 1st ring and 2nd ring,pay atte-
ntion to the upper and lower directions.The surface
with sign should be assemblied upward.
When installing the ring ,first installing the lower oil
scraping plate ,then install the oily plate ,finally
install scraping plate
After assembling, make sure that the piston rings
can turn smoothly between each other.
There should be a 120
interfaces between the rings,the splits of upper and
lower oil scraping plate of oil ring should stragger
about 20mm on the left and right sides of oily plate
split.
2.I nstallation:
Piston
Piston pin
Piston pin hoop
Note:
The arrow mark a on the piston should be tow-
ard the front side of engine.
Before installing the piston pin hoop,cover the cra-
nkcase with clean towel or cloth so as to prevent the
piston pin hoop or other articles falling into the cr-
ankcase.
3. Installation:
Dowel pin
Paper pad
4-62
.
angle difference for the
NEW
NEW
ENG