Yamaha 55DEHD - Maintenance specification

SPEC
2-5
6885J11
Specification
Maintenance specification
Power unit (55D, 75A models)
(*1) Measuring conditions:
Ambient temperature 20°C (68°F), wide open throttle, with spark plugs removed from all cylinders.
The figures are for reference only.
Item Unit
Model
55DEHD 75AEHD 75AED 75AET
Power unit
Minimum compression kPa 340
pressure (*1) at electric starter (kgf/cm
2
, psi) (3.4, 49)
Cylinder head
Warpage limit mm (in) 0.1 (0.0039)
(lines indicate straightedge
position)
Cylinder
Bore size mm (in) 82.000–82.020 (3.2283–3.2291)
Piston
Piston diameter (D) mm (in) 81.935–81.955 (3.2258–3.2266)
Measuring point (H) mm (in) 20.0 (0.79)
Piston clearance mm (in) 0.065–0.070 (0.0026–0.0028)
(reference data)
Piston pin boss bore mm (in) 19.904–19.915 (0.7836–0.7841)
Oversize piston
1st mm (in) 0.25 (0.010)
2nd mm (in) 0.50 (0.020)
Oversize piston diameter
1st mm (in) 82.185–82.205 (3.2356–3.2364)
2nd mm (in) 82.435–82.455 (3.2455–3.2463)
Piston pin
Outside diameter mm (in) 19.895–19.900 (0.7833–0.7835)
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