Checked spark plugs looks bit rusty and milky,,,,
I found full of water of inside cylinders. 
Sucked water from each cylinder
See how much water was sitting inside of cylinder also still more water sitting bottom of crank case,,,,,This customer rent his ski to his friend 3month ago then must be ski sank or forgot to stop tap water after flushing,,,,, anyway this ski was sitting last 3month with this condition, so now motor dameged,,,,,,,,,,
