Checking The Piston Clearance - Yamaha KT100SEC Owner's Service Manual

CHECKING THE ENGINE PARTS
Feeler gauge
Piston

CHECKING THE PISTON CLEARANCE

Method to use a feeler gauge.
●
Feeler gauge
How to insert the piston and the feeler gauge
is as shown: The piston pin is inserted in
parallel with the crankshaft axis.
Optimum piston clearance is evaluated by
smoothness of drawing out the feeler gauge.
Calculate the piston-to -cylinder clearance with
●
following formula.
PISTON
＝
CLEARANCE
* Refer to the following sections for inspection
method: CHECKING THE CYLINDER and
CHECKING THE PISTON AND PISTON PIN.
Standard piston-to-cylinder clearance
0.030∼0.035mm
CAUTION:
If out of specification, rebore or replace
●
cylinder, and replace piston and piston
rings as a set.
If the piston clearance is over specification,
●
rebore cylinder and replace piston with
oversized piston to meet the specification.
If piston is replaced with oversized piston,
●
piston ring should be replaced with the
equivalent oversized piston ring.
Piston size number
1
2
3
4
5
6
7
8
9
10
11
12
4-12
ENG
CYLINDER PISTON
−
BORE DIAMETER
Piston diameter(mm)
Piston ring size number
52.00
52.05
52.10
52.15
52.20
52.25
52.30
52.35
52.40
52.45 10
52.50 11
52.55 12
1
2
3
4
5
6
7
8
9