350 V8 OMC 1987 (Chevy) engine

Discussion in 'Gas Engines' started by YvonneDee, Jul 30, 2010.

  1. YvonneDee
    Joined: Jul 2010
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    YvonneDee Junior Member

    I'm new to this bear with me......I'm a girl. Purchased 1987 Celebrity 21 foot V-hull. (Salt Water Boat). Boat ran OK except secondaries would not open. Rebuilt carb, new cap, wires and spark plug. Replaced intake manifold (much corrosion from salt water). New electrical harness, 2 new solenoids. New throttle arm very corroded. It runs erratic can not go over 2000 RPMs or it does go over 2000 RPMs. Strong smell of gas. Swapped carb with 3 other carbs that were good. Still same thing. No one can figure this out. No vacuum leaks either. Any suggestions would be appreciated.confused:
     
  2. gonzo
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    gonzo Senior Member

    Do you know where the gas is coming from? Changing parts without determining the problem is bad troubleshooting. It ends up being very expensinve and usually not solving the problem. The fuel pump could be leaking.
     
  3. YvonneDee
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    YvonneDee Junior Member

    350 V8 Omc 1987

    Ok heres the short story. Its been at a marina for a year because they told me they were very busy. Got it back two months ago went to start it, no spark. They came and corrected the problem BUT there were no gauge lights except water temp gauge? You know the rest of the story. Now they are suggesting swapping the engine? I gave them till today to fix it. Then its going to another marina. NOTE: It back fires out the secondaries and they are sticking? I will call them and give them your opinion. VERY FRUSTRATING. Thank You!!
     
  4. gonzo
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    gonzo Senior Member

    It sounds like it is running worse now.
     
  5. CDK
    Joined: Aug 2007
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    CDK retired engineer

    There's a long list of possible causes, but like Gonzo said, exchanging parts without proper diagnosis is a waste of time and money.

    My bets are on the ignition, like bad capacitor or worn contact points. An often overlooked fault could be a defective rpm gauge. It gets its signal from the distributor and may present a load preventing buildup of sufficient spark energy with increasing rpm.
     
  6. YvonneDee
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    YvonneDee Junior Member

    350 V8 Omc 1987

    Quick update. Replace all wiring in boat. New Carb. Now they're saying it has a bad cam. Hope this will correct the problem. Thanks guys.
     
  7. scotch&water
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    scotch&water Junior Member

    We had a problem on an older OMC solved by replacing advance springs in the dist. a low cost fix
     
  8. YvonneDee
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    YvonneDee Junior Member

    350 V8 Omc 1987

    Thanks but they are saying the cam is bad. They are also checking that as well. Thanks again.
     
  9. kenJ
    Joined: Jul 2005
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    kenJ Senior Member

    In my experience camshafts don't go bad. Sounds to me like they are after your money, not your well being.
     
  10. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Maybe this is a camshaft with a "best before" label....
     
  11. gonzo
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    gonzo Senior Member

    350 camshafts rarely go bad. I think you should ask for a commitment from them. If the job doesn't fix the problem you shouldn't pay for it. That is the guarranty I give my cusotmers.
     
  12. broke_not
    Joined: Jun 2008
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    broke_not Junior Member

    Camshafts do go bad, but it's not a common failure. I took one out of a 350-powered tow truck years ago that had 2 lobes that were nearly flat. Since this was in a truck that rarely saw highway duty, (it basically ran around town at 20-25 mph doing jump starts and occasional towing), it didn't become "apparent" until the lobes were almost completely flat causing a constant miss.

    If your marina has done all they've done so far and only now figured out the cam is bad, they're pretty much clueless. Wow....

    At the very least, they need to tell you in detail how they've determined the cam is bad. Sounds like it's just the next part they want to throw at it.

    ;)
     
  13. scotch&water
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    scotch&water Junior Member

    It sound like they're getting in to your pocket book. Some thoughts a long block marine 350 eng. <that is every thing for the basic eng. without the bolt on parts,> this can be had for under 2500.00 the labor to remove and replace most areas will be in the 1000.00 range. Now the word will be that the manifolds are bad and more $ . So since we are dealing with an OMC yuk and if I liked the boat a lot, my thoughts would be to look for a frishwater boat wrecked that has a 350 with Mercruiser drive and have that swapped out, add a fresh water cooling kit if one is not installed
     
  14. YvonneDee
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    YvonneDee Junior Member

    Well the cam is ok. They replaced a lot of wiring. Got the boat back ran it in yard sounds great. Dropped it in lake had a little trouble planing out. Put some weight in cuddy. Running great for an hour and then it quit. Check the fuses, ok. Still no spark. Then checked ignition wire connecting to fuse. VERY loose. Crimped the connector. Still loose. Had to hold wire to maintain contact to get back. That's a easy fix. Scotch&water replaced manifolds and risers and also kit. New lower unit too. Still no gauges work except oil pressure. Taking elsewhere for that. Perhaps a bad ground. They left a lot of wire hanging loose. I'm done with these guys. Next is cosmetic's. Thanks to everyone!!
     

  15. CDK
    Joined: Aug 2007
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    CDK retired engineer

    So post #5 wasn't very far off.
     
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