Инструкции По Обслуживанию для kymco mo bw250

• The cylinder and piston can be serviced with the engine installed in the frame.
• When installing the cylinder, use a new cylinder gasket and make sure that the dowel pins are

correctly installed.

• After disassembly, clean the removed parts and dry them with compressed air before inspection.

Standard (mm)

Service Limit (mm)

Item

SH50CA
SH25CA

SH50CA
SH25CA

I.D.

72.705_

72.715

72.80
52.50

Warpage

0.01
0.01

0.05
0.05

Cylindricity

0.01
0.01

0.05
0.05

True roundness

0.01
0.01

0.05
0.05

Ring-to-groove

top

0.2

0.09
0.09

clearance

Second

0.015_

0.050

0.015_

0.050

0.09
0.09

top

0.1_

0.25

0.15_

0.30

0.50
0.50

 Piston,

Ring end gap

Second

0.15_

0.30

0.15_

0.30

0.50
0.50

 piston ring

Oil side rail

0.25_

0.7

0.2_

0.9

æ
æ

Piston O.D.

72.67_

72.69

52.370_

52.390

72.6

52.30

Piston O.D. measuring position

9mm from bottom of skirt

9mm from bottom of skirt

.

Piston-to-cylinder clearance

0.010_

0.040

0.010_

0.040

0.01
0.01

Piston pin hole I.D.

17.002_

17.008

15.002_

15.008

17.04
15.04

Piston pin O.D

16.994_

17.000

14.994_

15.000

16.96
14.96

Piston-to-piston pin clearance

0.002_

0.014

0.002_

0.014

0.02
0.02

Connecting rod small end I.D. bore

17.016_

17.034

15.016_

15.034

17.06
15.06

• When hard starting or poor performance at low speed occurs, check the crankcase breather for

white smoke.  If white smoke is found, it means that the piston rings are worn, stuck or broken.

• Worn or damaged cylinder and piston rings

• Worn or damaged piston rings

• Worn, stuck or broken piston rings

• Worn or damaged cylinder and piston

• Excessive carbon build-up in combustion

• Worn cylinder, piston and piston rings

chamber or on piston head

• Worn piston pin hole and piston pin

• Incorrectly installed piston

Cylinder