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1996 7.4 Gen 5 loose of power-gctid818189

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    1996 7.4 Gen 5 loose of power-gctid818189

    Here's the story.

    The boat was running great until 2 weeks ago. My marina does not sell gas, so I haul 20 gals of non ethanol at a time form a local station. I put the gas in the boat and it ran fine for a 30 minute sunset cruise . The next day we went out and it started out fine, after we floated for a while the boat was hard to start. I started back to the marina and the power just went down hill to the point I thought I was going to have to be towed. I was no more than a mile out in the sound. By the time I got back I was barely making hull speed. It did make a strange rattleing noise for about a second, half way back to the dock.

    So I figured the fuel was bad.

    Last week end I brought fresh fuel in a 6 gal mobile tank from another station. I pulled the plugs (new this spring) they were black with carbon, so I replace them. While I was at it I did a compression test I had 125lbs on all except cylinder 7 had 150lbs. cylinder 1 had 135lbs. I emptied the separator, it had some red water in it. I know there is no rust in my tank. I hooked up the mobile tank and it started right off. I let it idle for 10 mins burning off the bad fuel. I left the dock and it ran at about 1/2 power the water temp is about 50 warmer than usual now 185 degrees.I ran about 15 mins hoping it would get better, it never did. I didn't shut it off until I got back to the dock and it was hard to start again. I checked the oil, no water in it, check the fuel flow it was OK, after it cooled down I pulled a plug and it looked good. Then it stated right up again, there is no unusual noises from the engine. It burned about 3.5 gals of fuel during the 15 min run.

    I thought sure it would run right with the fresh fuel.

    Any thoughts on what I should check next. Could it have jumped time, is that why it's running hotter? I haven't pulled the carb yet because I rebuilt it last spring.

    Thanks Lee
    Albermarle Sound, NC
    1996 Ciera 2855
    7.4 Merc Bravo 3
    MMSI 338223458

    Water in the separator? You ran her with a new filter and on the external fuel tank as a test and have the same results? Double check the timming? It could be a ignition coil going out.
    Edmonds, WA
    "THE FIX" '93 2556
    Carbureted 383 Vortec-Bravo II
    The Rebuild Of My 2556
    My Misc. Projects