Please explain how the tell-tale pipe coming off seized the motor?
I had a similar problem with our Honda BF50 last week. The pipe connecting the the engine block outlet and engine pan outlet spiggot popped off. The result being, the engine pan filled with seawater which caused the motor to cough and splutter when the electrics eventually became submerged.
I got it home, rinsed the heck out of it, let it dry and gave it all a liberal spraying of DWF. The dipstick was also submerged, although a 'sealed' unit, I decided to give it a precautionary oil changed including an expensive Castrol GTX 10w40 flush.