Diesel advice needed
- Thread starter higgs
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It's air in your fuel system. Had this happen many times over the years. Boat (S2 8.5) has rectangular fuel tank with pick-up tube located far to one side. With anything less than half a tank, air could enter the tube, engine running or not, when the boat was heeled. Kept tank full to prevent problem until finally relocating pick-up tube to center of tank. Never had a problem since. Yanmars will run, though poorly, for a long time with air in the system and what you described is exactly what they do.
This is very interesting reading. I have a 3gm and m on the bay of quinte. comming home from the 1000 islands last weekend my engine would drop 500 rpm for no reason and then 20-30 seconds later would be right back to full strength with it repeating over and over ever 2-5 minutes. Sailed for a couple hours and had no problem again the rest of trip. It has done this before. I like the quote something in the water. But have no idea why it was bogging out.
Exhaust Elbow
Guess. My exhaust elbow clogged suddenly on a trip from Cape Cod canal to Boston, pulled into Scituate harbor, sailed onto mooring, loss rpm's, ect. sounds similar, I had diesel mechanic show me old elbow clogged, new one installed, works great.
Guess. My exhaust elbow clogged suddenly on a trip from Cape Cod canal to Boston, pulled into Scituate harbor, sailed onto mooring, loss rpm's, ect. sounds similar, I had diesel mechanic show me old elbow clogged, new one installed, works great.
Attachments
I've had this problem for the last couple of years. Originally my 1GM was very hard starting. I found that the bleed screw was broken off... a combination of a drilled vent hole and a brass screw made it extra susceptible to breakage. I bled the system but have been having this intermittent problem as described since. I'm going to rebleed the system tomorrow & hope for better results.
Diesel Advice
You have recieved some good advice, all good, all possible. I have not read any postings telling you to check your fuel filter gaskets though. I have over a million logged miles with Catapilar engines(not Yanmar, but this advice is universal). I have seen this same problem after fuel filter changes before. When you replace the filter the old gasket will stick to the filter base from time to time. If don't notice you'll put the new on over the top of the old and it will cause air to enter the fuel system intermitantly. I only add my two cents because you stated you recently changed fuel filters. Good luck, I can tell you from hard learned experience that the problem will not correct itself. It may seem to have gone away, but it will jump up and bite you at the most inoportune time.
You have recieved some good advice, all good, all possible. I have not read any postings telling you to check your fuel filter gaskets though. I have over a million logged miles with Catapilar engines(not Yanmar, but this advice is universal). I have seen this same problem after fuel filter changes before. When you replace the filter the old gasket will stick to the filter base from time to time. If don't notice you'll put the new on over the top of the old and it will cause air to enter the fuel system intermitantly. I only add my two cents because you stated you recently changed fuel filters. Good luck, I can tell you from hard learned experience that the problem will not correct itself. It may seem to have gone away, but it will jump up and bite you at the most inoportune time.
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