Motive Power Industry Bugxter BR-150, Service Manual, Page: 36 / 75

ENGINE INSPECTION 7
Engine inspection
• Pulse air
system
• Keep the air-in
path clean.
• Keep the
vacuum pipe
well connected
to intake
manifold,
• Never jam the
vacuum pipe.
Part name /description
Standard
( mm )
Limit
( mm )
Cylinder head
flatness
Cylinder
Bore 57.490~57.510 57.600
Curve
- 0.05
Cylindrility
- 0.05
Roundness
- 0.05
Piston/
Piston ring
Clearance b/w Piston and
Piston ring
lst ring 0.10
2 n d ring
0.10
Clearance of cutting
section
lst ring 0.50
2
n d
ring
0.50
---
Piston outer diameter
57.475~57.490 57.400
Measuring location of piston outer dia . 5 mm from the lower end of skirt
Clearance b/w piston and cylinder 0.025~0.035 0.10
Piston pin hole inner dia 15.006~15.012 15.030
Piston pin hole inner diameter
14.990~14.992 12.96
Piston pin outer diameter 0.020~0.017 0.025
Clearance between piston and piston pin
15.010~15.028 15.060
Connecting rod small end inner dia
Cylinder & piston inspection data: