Maintenance Specifications; Engine - Yamaha 50G Service Manual

SPEC
C31000-0*

MAINTENANCE SPECIFICATIONS

ENGINE

Item
Cylinder head:
Warpage limit
(Lines indicate straight
measurement)
Cylinder:
Bore size
Taper limit
Out of round limit
Piston:
Piston to cylinder
clearance
<Limit>
Piston size "D"
Measuring point "H"
Oversize
Offset
[direction]
Piston ring:
Sectional sketch
Top ring & 2nd ring
End gap [installed]
Top ring & 2nd ring
Side clearance
Top ring & 2nd ring
*: Except for USA
MAINTENANCE SPECIFICATIONS
Unit
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
1st mm (in)
2nd mm (in)
mm (in)
Type
B mm (in)
T mm (in)
mm (in)
mm (in)
50 hp 60 hp 70 hp
72.00 ~ 72.02
(2.834 ~ 2.835)
0.050 ~ 0.055
(0.0020 ~ 0.0022)
0.105 (0.0041)
71.945 ~ 71.970
(2.8325 ~ 2.8335)
72.25 (2.844)*
72.50 (2.854)
0.5 (0.0197)
[Exhaust side]
3.0 (0.12)
0.3 ~ 0.5 (0.012 ~ 0.020)
0.03 ~ 0.07
(0.0012 ~ 0.0028)
2-5
Model
75 hp 80 hp
0.1 (0.004)
82.00 ~ 82.02
(3.228 ~ 3.229)
0.08 (0.003)
0.05 (0.002)
0.060 ~ 0.065
(0.0024 ~ 0.0026)
0.115 (0.0045)
81.935 ~ 81.960
(3.2258 ~ 3.2268)
10 (0.4)
82.25 (3.238)*
82.50 (3.248)
1.0 (0.039)
[Exhaust side]
Keystone
2.0 (0.08)
3.2 (0.13)
0.4 ~ 0.6 (0.016 ~ 0.024)
0.03 ~ 0.06
(0.0012 ~ 0.0024)
E
90 hp