Announcement

Collapse
No announcement yet.

Bringing an engine back to life

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

    Bringing an engine back to life

    I've got a 2855 with a 454 chevy 7.4L Mercruiser that has been sitting for 10 years or so.

    Is there a way to turn it over by hand?

    I've had a mechanic change the oil, filter, squirt some oil down the cylinders, install new plugs, and now it's time to nudge it back to life. But the mechanic I have working on it says there appears to be no access to a flywheel or bolt to turn the motor over. If there's nothing, we're probably just going to crank it under power tomorrow. That's probably OK. I wanted to be a little more gentle on the first turn.

    Suggestions?

    #2
    Disconnect the coil wire and crank the engine until it shows oil pressure for at least a few seconds. Then reconnect the coil wire and start it up. Cranking it will put oil back on the journals but will also fill the carb with fuel. If you want to oil it before you crank it pull the distributor and run the oil pump with a drill until there is oil pressure then reinstall the distributor.


    my 454's sat for almost 10 years both fired right up.
    1989 Avanti 3450 Sunbridge
    twin 454's
    MV Mar-Y-Sol
    1979 Bayliner Conquest 3150 hardtop ocean express.
    Twin chevy 350's inboard
    Ben- Jamin
    spokane Washington

    Comment


    • Nauti_Mike
      Nauti_Mike commented
      Editing a comment
      Agree, disconnecting the coil 12V on the positive terminal will disable the ignition.

    #3
    You could spin the oil pump ... i used a old dizzy shaft, however they sell a tool .

    https://www.ebay.com/p/Speedmaster-E...5253016&chn=ps
    Be good, be happy, for tomorrow is promised to no man !

    1994 2452, 5.0l, Alpha gen. 2 drive. Sold ! Sold ! Sold !

    '86 / 19' Citation cuddy, Merc. 3.0L / 140 hp 86' , stringer drive. Sold ! Sold ! Sold !

    Manalapan N.J

    Comment


      #4
      I would pull the plugs
      spin it with the starter to get op. And then reinstall plugs and spin it again with the coil wire off
      Then go for the start
      1992 2452
      5.0 alpha1 gen2

      Comment


        #5
        Agreed...spin the oil pump first until you get some pressure...reinstall the distributor (carefully aligned, of course), disconnect 12V to coil, take out spark plugs, crank it over with the starter (this will make sure oil get into the nooks and crannies that spinning the oil pump didn't take care of). You may need to go around a couple of times to line up the distributor as the oil pump shaft will need to align to distributor shaft...not a problem. Cranking it without the plugs will make sure the lifters get pressurized again...do this several times until you're sure you're getting oil up the pushrods... To make reinstalling the distributor easier, put #1 at top dead center (intake and exhaust valves closed, both rocker arms loose)

        Then put plugs back in, hook up ignition to coil and let 'er rip...
        1988 3888
        Twin Cummins 6BT's 210hp
        Onan 8.0
        Boating Raritan Bay

        Comment


          #6
          Originally posted by Infyinfy View Post
          I've got a 2855 with a 454
          Is there a way to turn it over by hand?

          I've had a mechanic change the oil, filter, squirt some oil down the cylinders, install new plugs, and now it's time to nudge it back to life. But the mechanic I have working on it says there appears to be no access to a flywheel or bolt to turn the motor over. If there's nothing, we're probably just going to crank it under power tomorrow. That's probably OK. I wanted to be a little more gentle on the first turn.

          Suggestions?
          No access to the flywheel for sure but what about the crank balancer? If space is tight up there removing the crank pulley should give you enough clearance to bolt on a tool or you can just use the pulley bolts and a bar to rotate it some, plugs out of course.

          Dave
          Edmonds, WA
          "THE FIX"
          '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
          (.030 over-Vortec top end-part closed cooled)
          The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
          Misc. projects thread
          https://www.baylinerownersclub.org/f...56-gctid789773

          Comment


            #7
            With the plugs out you might be able to turn it over once or twice with the belts
            just flex them tight and pull the motor around with the belt.
            DONT run your fingers between the belt and a pulley. It hurts trust me!
            1992 2452
            5.0 alpha1 gen2

            Comment


              #8
              I would want to turn it by handa few revs to make sure i didnt have a valve hung open.
              1992 2452
              5.0 alpha1 gen2

              Comment


                #9
                Main question is whether it is frozen solid or not at this time. If it is frozen, you may break starter or flywheel gear. I would remove the outdrive, your mechanic should have a spare driveshaft yoke (or you can use yours after disassembling u-joints, it will be good to change them anyway) put it in the coupler and try to turn. I had good luck doing it on my friend's inherited boat.
                Alex
                1997 2859, 7.4 MPI, Bravo II
                1993 2452, 5.7 Bravo II - SOLD

                Comment


                  #10
                  Speaking of valves...I would pop the rockers and replace the valve keepers...you can do this by holding the valves against the seats with compressed air in the cylinder. Also inspect the pushrods to make sure none are bent from sitting against an open valve. Inspect the mating faces of the rockers for rust...don't want to chew into valve stem or pushrod.

                  Keep in mind also that some of the springs have been kept compressed for 10 years and may have weakened... If that engine is going to be in a higher RPM application, I would replace the valve springs.
                  1988 3888
                  Twin Cummins 6BT's 210hp
                  Onan 8.0
                  Boating Raritan Bay

                  Comment


                    #11
                    If not wanting to play with the distributor, believe "pre" lubrication can also be done by pumping oil through the fitting for oil pressure switch. Guess a slightly modified lube oil pump with warm oil from a bottle would work good enough?
                    Bayliner 2556 1990 project

                    Comment


                      #12
                      Update.. we primed the engine as advised and replaced one of the batteries. Metered it and the charge looks good.

                      But the starter doesn't seem to engage. We hotwired the ignition at the helm (keys lost) and hear a click in the engine bay. Sounds like a relay. But no motion/life on the starter motor. Other than a relay click there's no sound.

                      We suspect the starter is bad. Going to pull it and test.


                      Click image for larger version

Name:	20180809_190538.jpg
Views:	2
Size:	286.8 KB
ID:	448023
                      Attached Files

                      Comment


                        #13
                        There is a slave soleniod on top of the engine near the engine breaker. Verify it is sending 12V to the starter soleniod when the key is in the start position. You can also jumper 12V directly to the starter soleniod to see if that helps.
                        1997 Maxum 2400 SCR 5.7LX Bravo II

                        Mike

                        Comment


                          #14
                          Like Mike said check the slave first and then the solenoid at the starter.
                          Were you able to move the crank by hand first?
                          Dave
                          Edmonds, WA
                          "THE FIX"
                          '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
                          (.030 over-Vortec top end-part closed cooled)
                          The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                          Misc. projects thread
                          https://www.baylinerownersclub.org/f...56-gctid789773

                          Comment


                            #15
                            I would remove the spark plugs and crank it until a minute after it shows oil pressure, This is done to circulate the oil without a heavy load (compression) then re-install the plugs and fire it off.
                            Captharv 2001 2452
                            "When the draft of your boat exceeds the depth of water, you are aground"

                            Comment

                            Working...
                            X