No, I did not check timing on other engine. BUT, I ran the boat yesterday. Got on plane and ran at 2800 RPM for 5 miles and everything is running perfect. All the gauges are right where they are supposed to be. Got back to my dock and shut down and checked oil and coolant. I used IR gun and took temps on elbows, exhaust manifolds, shafts. Both engines were real close on temps and all fluids were fine. Sooooo, FIXED!!!!!
Now the question, What was it?? My theory is that when it exploded, the blast cracked both exhaust manifolds as my pressure test in water tank proved. I had one sticky exhaust valve and I'm sure the head gaskets suffered some damage.
Lessons learned? First is use the right tools for diagnostic testing. My compression test and leak down test were done with cheap equipment and my air compressor used for the leak down test had a leak in the hose that was buried, and I did'nt really know how to interpret the numbers.
Going to get her cleaned up and take the bride out for a boat ride and lunch at the beach.
Thanks MakoMark, you are invaluable in your straight thinking and knowledge.