Hello All,
I have a 1989 Bayliner 2556 with an 240HP V8 OMC 305 and the Cobra outdrive. Over the winter I had a lot of work done on the boat including winterizing service, engine tune up and service, outdrive service, carb rebuilt, new starter. I took the boat out and after about 15 minutes of running at about 3/4 throttle the engine started to bog down. It ran very well up to this point, so I decided to bring it back to the marina and start the troubleshooting process.
I started by inspecting both of the fuel filters, which showed no water in the inline filter and the little filter in the carb was totally clean, but I went ahead and replaced them anyway. Next (after reading some forums) I checked the vent line on the fuel tank, which was totally clear (some people had reported nests being built in them). I pulled the flame arrestor off and and ran the boat and it seems to be getting plenty of fuel. I did notice that in the secondary jets, one side was getting more fuel (a little) than the other, so I puled the carb off and sent it back to the guy who rebuilt it and had him look at it. He check it out and didn't find anything wrong and said a little more fuel on one side is not uncommon.
I took it out about a week later and same thing. Boat ran good for about 10-15 min then serious loss of power. At this point I had a mechanic come out and inspect. He found that the gaskets were bad between the exhaust manifold and risers, so we replaced them. He said that there could be water leaking into the manifold and could cause the problem. We also did a compression test and got good compression in all of the cylinders (spark plugs all looked good too). I am not seeing any increase in temp and verified that I am getting good water flow through the exchanger.
I can run for hours at lower RPM (about 1/4 throttle) with no problem, but I can't get the boat over 3000 RPM and it feels really sluggish past ~1/2 throttle. Also, once the boat is warm, if I back down to idle the engine dies, so I have to rev it up to about 1000 RPM. I am running out of ideas. I am thinking about replacing the carb, but that could is just a shot in the dark.
Anyone ever have this problem or have any ideas?
I have a 1989 Bayliner 2556 with an 240HP V8 OMC 305 and the Cobra outdrive. Over the winter I had a lot of work done on the boat including winterizing service, engine tune up and service, outdrive service, carb rebuilt, new starter. I took the boat out and after about 15 minutes of running at about 3/4 throttle the engine started to bog down. It ran very well up to this point, so I decided to bring it back to the marina and start the troubleshooting process.
I started by inspecting both of the fuel filters, which showed no water in the inline filter and the little filter in the carb was totally clean, but I went ahead and replaced them anyway. Next (after reading some forums) I checked the vent line on the fuel tank, which was totally clear (some people had reported nests being built in them). I pulled the flame arrestor off and and ran the boat and it seems to be getting plenty of fuel. I did notice that in the secondary jets, one side was getting more fuel (a little) than the other, so I puled the carb off and sent it back to the guy who rebuilt it and had him look at it. He check it out and didn't find anything wrong and said a little more fuel on one side is not uncommon.
I took it out about a week later and same thing. Boat ran good for about 10-15 min then serious loss of power. At this point I had a mechanic come out and inspect. He found that the gaskets were bad between the exhaust manifold and risers, so we replaced them. He said that there could be water leaking into the manifold and could cause the problem. We also did a compression test and got good compression in all of the cylinders (spark plugs all looked good too). I am not seeing any increase in temp and verified that I am getting good water flow through the exchanger.
I can run for hours at lower RPM (about 1/4 throttle) with no problem, but I can't get the boat over 3000 RPM and it feels really sluggish past ~1/2 throttle. Also, once the boat is warm, if I back down to idle the engine dies, so I have to rev it up to about 1000 RPM. I am running out of ideas. I am thinking about replacing the carb, but that could is just a shot in the dark.
Anyone ever have this problem or have any ideas?
