Join Date: Jan 2008
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I bought a brand new turbo from Yanmar, installed it and it made no difference at all. So turbo is ruled out and the money darts game continues. It really shocks me that diesel mechanic is pretty much like being a weather man.
So we have tried new injectors, a new lift pump, a new turbo, the after cooler was cleaned out and we have run various tests and sea trials and I am still at square one except for the $3K that is gone.
I have no means of testing the exhaust back pressure but the mixing elbow is clear and in great shape and the giant hose that leads from it to the fiberglass waterlift muffler is clear. Also, the engine does not run hot at all and water spits from the transom exhaust pretty much as it always has. I see no indications of any blockage and other than replacing all the parts (huge money and massive labor) I see no way to determine if this could be the problem or not.
Incorrect prop pitch has been suggested by many….. the boat was hauled a month ago and the prop and shaft were cleaned. Also, I had a diver check the prop out on Friday of last week and he found it clean with no issues and said it operated as a max prop should.
During this refit I did add about 2000lb to the boat… a new arch, deck boxes, solar panels, a larger battery bank plus all my tools and all our cruising gear. The tech I spoke to at max prop seemed to think this addition unlikely to cause such a change in engine behavior on a boat my size but he did not say it was impossible. The Yanmar tech at Mastry insists that the issue is prop however. I am very skeptical…. How could I go from getting 3400 rpm with little black smoke to pouring black smoke and only getting 2,950rpm by adding 2Klb to a 35,000lb boat?
But, with no other good ideas or solutions presenting themselves our plans are to haul the boat and reset the prop pitch. Another money dart being loaded up…..
I swear I am getting into the diesel mechanic racket. Throw parts at it until something sticks and cash the checks all down the line.