07 March 2019 | Boca Chica, Dominican Republic
After a challenging passage across Mona Passage between Puerto Rico and the Dominican Republic, we had to focus on fuel contamination. The impact was that our engine had less and less power. We motor/sailed as the wind was light. The sea state was agitated. And when direct downwind, we have a difficult time keeping the genoa filled with wind. The seas are constantly messing with a well-filled sail. When we made port in Boca Chica, we looked for a mechanic. Much of our problem occurred shortly after picking up a lobster buoy and line. So we checked the prop, then the shaft, then the cutlass bearing: ok. Then the transmission, replacing the ATF fluid and filter. The tranny pressure in forward and reverse was good. So on to the engine. First I serviced the turbo, cleaned it, and spun the blades freely. I explained to the mechanic that I had serviced both RACOR filters which had been overwhelmed by water and diesel bugs. I had replaced the primary fuel filter on this Yanmar, and bled the oxygen out of the line. We ran a couple tests: in neutral at the dock we could get 3400 rpm which was great. In gear forward and reverse at the dock, we could only get 1000 rpm which was bad. He looked at the exhaust for smoke. When under load, the exhaust water had black in it. So he started focusing on the fuel injector pump (the heart of the fuel delivery in the diesel engine). After a time he made some adjustments, ran the engine under load at the dock and was able to attain 2100 rpm which is great for the Max Prop setting that we use. We took the boat out for a 'high speed run'. He was checking for smoke: nada. We were set!! His theory was that the contaminated fuel had done some internal damage that for the moment was correctable. We will have the injector pump serviced, and/or replaced back in Portland. Today we had our four fuel tanks polished Dominican Republic style. All fuel was removed through a couple of high volume RACOR filters. The tanks were totally emptied, then wiped down with rags by hand as much as the tank baffles would allow. Then the polished fuel was returned to the tanks, minus several gallons of water and diesel bugs. I am imagining a happy face on our Yanmar! Clean fuel is king!