Where can i find the serial # on a yamaha outboard motor?

Question

or what does it start with?

Answer 1

There  is one generally on the block , underneath the cowling. There is another stamped intermediate housing.

I have also seen it on the mounting unit.

Answer 2

there is usually a plate that is stamped with the information, on my old fifty it was on the upper right inside of the leg ( driverseat perspective)

Answer 3

If your missing the serial# plates. 9 times out of 10, the motor is stolen. In the USA by law the freeze out plug has the serial number on it. If the plug is blank, someone most likely put epoxy on it to cover #s. If plug#s do not match plate#s motor maybe stolen. All outboards have a plate riveted to mount.