Piston
l
Remove the ring piston top (1st) (A), piston ring
2nd (B) and oil rings (C) along with separator oil
ring (D). (Fig. 3.88)
Caution:
Do not expand the rings more, it may lose
it‘s mechanical properties.
l
Decarbonise the piston and piston ring
grooves. After cleaning the grooves, fit the
rings and rotate them in their respective
grooves to make sure that they rotate freely.
(Fig. 3.89)
l
Carbon in the grooves is liable to cause the
rings piston to stuck in the grooves, and this
will lead to reduced engine power output.
Note:
While cleaning the ring grooves of the
piston, take care not to damage the
grooves. Use an old broken ring to clean
the grooves.
l
If a piston sliding surface is badly scored or
scuffed due to overheating, it must be
replaced. Shallow grooves or minor scuff can
be removed by smoothening with a fine emery
paper (400 grade). (Fig. 3.90) Inspect the piston
for damage or crack. Replace if required.
l
Measure the diameter at the right angle to the
pin piston and at a point which is 10 mm from
the bottom to check wear. If the diameter is
lower than the service limit, replace the piston.
(Fig. 3.91)
Outside micrometer
Size
Grade
Standard
Service Limit
(in mm)
(in mm)
–
A
65.960 ~ 65.965
–
B
65.965 ~ 65.970
65.00
–
C
65.970 ~ 65.975
1st OS
PINK 66.215 ~ 66.220
–
2nd OS
WHITE 66.465 ~ 66.470
–
l
Cylinder to piston clearance is the difference
between piston diameter and bore diameter.
3-27
TVS APACHE RTR 200
SERVICE MANUAL
SERVICING OF ENGINE
Fig. 3.88
A
D
B
C
Fig. 3.89
Fig. 3.90
Fig. 3.91
10 mm
