Motor locked up

[sourjane]

I have a 50hp yamaha outboard motor 4 stroke 2004 ..ran fine for about 20mins and quit..fired back up for a few sec ..got back to lauch pull plugs and can not turn flywheel. Plz

 

[DangarStu]

I'd drop the gearbox off to confirm that it is the powerhead that won't move and not a seized gearbox.

Stuart