Cylinder Measurement And Check; Standards Of Clearances For Various Piston Rings; Installation Of The Piston - PGO Tigra AF-125BAE Service Manual

Measurement and check
1. Visually check the external of the piston or replace it with a new one in the event of the old one
useless.
2. Check the inner diameter of the piston pin (standard size: 15mm; size limit: 15.040mm) or replace
the old one in the event of the bore out of the size limit.
3. Check the outer diameter of the piston pin (standard size: 15mm; size limit: 14.960mm) or replace
the old one in the event of the bore out of the size limit.
4. Measure the piston's outer diameter at 7mm below the skirt and 90
size: 52.4mm; size limit: 52.3mm).
5. Check the level of the cylinder surface.
Limit—0.05mm; correct or replace the cylinder.

Standards of clearances for various piston rings

Item
Clearance between the
piston ring groove and
the piston ring
Clearance of the piston
ring gap
Install the cylinder and the piston

1. Installation of the piston

A. Sequentially install piston rings on the piston
B. Apply engine oil around piston rings.
Note: Do not scratch or break any piston ring.
"R" marks should face up during assembly.
The angle between the first ring's gap and the second
ring's gap should be not less than 120 degrees; gaps
should not be placed at the piston pin.
C. Install parts such as piston, piston pin and grip ring for piston pin.
Note: The arrow mark on the piston' top should face the
exhaust valve during assembly. To avoid any grip ring dropped
into the crankcase, please take a piece of clean cloth to plug the
crankcase.
Piston ring
Fist
Second
First
Second
55
Cylinder Assembly
o
from the piston pin (standard
Standard size
0.015mm~0.050mm
0.015mm~0.050mm
0.10mm~0.25mm
0.25mm~0.45mm
7mm
Limit
0.090mm
0.090mm
0.50mm
0.65mm
7