2009 Yamaha F40 Outboard Service Manual, Page 233Get this manual
Power unit
a 10.0 mm (0.39 in) 48.0 mm (1.89 in) 85.0 mm (3.35 in) Cylinder bore (D1D6): 65.00065.015 mm (2.55912.5596 in)
Checking the piston diameter
Power unit
a 10.0 mm (0.39 in) 48.0 mm (1.89 in) 85.0 mm (3.35 in) Cylinder bore (D1D6): 65.00065.015 mm (2.55912.5596 in)
Checking the piston diameter