I recently bought a boat with a "81" 90hp Evinrude that sat in a garage for 12yrs. I run it once, but it died after about 10 minutes. how do I take the lower unit off, and replace the water pump.The heads were so hot, I couldn't touch them.(It was peeing). I guess I have to check the water (jackets)? too.I have all the bolts out,and it dropped about 1 inch and thats it.