...and for those following this epic saga...
We had a successful sea-trial last night. I still do not believe it and I am waiting for something to go wrong.
Before the trial, the marine mechanic pulled the air intake and was surprised to see the gasket in pretty good shape. But there was oil on both sides of it. He pulled the rest of the injectors and they looked okay, but we went with the refurbished injectors we bought (on E-Bay). He tested them before installing them and he said they looked and performed like they were new. He cleaned the fuel rail and then started to put it all back together, making sure the new air intake gasket was solidly secured. He said "the next guy that takes that thing off will really be working hard."
With the air intake manifold off, he did notice some places around the manifold where oil had "splashed" or "sprayed" up onto other parts of the system. He checked the oil reservoir and found it was grossly overfilled. He tried to explain to me (and I did not understand a word) about the problems of oil overfill and how oil can get into places it should not, being sucked into the intake, causing the engine to run lean. Whatever. It was another issue that he found and corrected.
We put the boat in last evening for the sea trial and she fired up nicely. We slowly motored out to open water and I put some load on the engine to bring it out of the hole and she popped out of the water like a leaping orca. Within seconds I was planed out and, with the engine at 3k rpm scooting across the Salish Sea. I had not felt power like that in years. The engine was steady. No hiccups, drops, coughs, just a smooth sound. Of course, in previous mechanics notes they ran for about 20 minutes before they lost power. We stayed on the water in various stages from trolling to acceleration to as high a speed as I felt safe (about +/- 35mph at 3800 rpm) for about 45 minutes. The boat felt like it did when we first had it new. That was many years ago. I will run a few more shorts tests (other islands are just 2-miles away) and it will be light-duty for the boat in an area where I can get help if needed. Just cannot truly believe we may have turned a corner.
The mechanic and I were talking about all the things that have been done to this boat in my search for the engine problem.
New fuel pump
New exhaust manifolds
Removing the stuck flapper from the exhaust system
New key cylinder
New Anti-syphon valve
New temp sensor and gauge (separate from the failing four winns gauge panel)
Electrical / battery rewiring
All new belts
New spark plug wires
Four or five sets of spark plugs (current set are NGK)
New batteries
New A/I gasket
New (refurbished) injectors
...probably more I can't recall and I haven't even gotten to the trailer repairs I had to make...
I'll post the final report when we get back. I'll add some pictures, too.
Mark