1964 Merc 350 question

Home › Forum › Ask A Member › 1964 Merc 350 question

Viewing 6 posts - 1 through 6 (of 6 total)
  • Author
    Posts
  • October 13, 2016 at 6:28 am #5485
    david-bartlett
    Participant

      I recently bought a boat that has a 1964 Merc 350 35hp on it. The motor is currently stuck, and I have not had time to see why. At this point all I have done is pull the plugs and squirt some penetrating oil in the cylinders.

      I bought the boat planning on replacing the motor, but have been thinking(Second mistake after buying the boat) maybe I can save it. It has controls and the wiring harness attached to it, but I see no key switch anywhere. Can this motor be pull started by just un-plugging the wiring harness from the side of the motor, or is it more involved than that?

      Once I get some time, I will pull the cover and recoil and try turning the flywheel with a breaker bar or something to see if it will free up and then go from there and clean the points, carb, etc.

      October 13, 2016 at 6:37 am #45743
      dave-bernard
      Participant

        US Member

        yes it can be started with out a battery just pull the wiring harness. check the lower unit for oil or rust may be stuck down there. if the power head is bad you can replace it with a merc 500 powerhead and cowls (63-64) no later. key # is on the switch inside the box.

        October 13, 2016 at 4:24 pm #45772
        outbdnut2
        Participant

          US Member

          Check first to try and find out what is stuck. Betty Ann mentioned the lower unit. I’ve seen a broken vane on a water pump impeller stick an engine. I currently have one with a mouse nest in the lower cylinder.
          To check for stuck pistons/rings, take out the spark plugs and put a long screwdriver or other metal bar into the spark plug hole until it touches the piston. Hold the screwdriver with one hand while you try to rock the flywheel back and forth with the other hand – even if moves little or none. If only one piston is stuck, often you will feel the other piston move slightly as a "tick" on the screwdriver. If you feel it on both pistons, look elsewhere for the jam-up. If the driveshaft is totally seized in a bad bearing, this method probably won’t work work.
          Often you can move the flywheel back and forth some when pulling the starter rope will not move anything, and rocking it back and forth can help unstick pistons.
          Dave

          October 15, 2016 at 2:17 am #45866
          david-bartlett
          Participant

            Power head is now free. I removed cowl/recoil and used a ratchet on the crankshaft nut and it let go. I squirted some more goo inside and turned it over several times and will leave it for now. Too many other things going on, but I will get it inside for Winter work, now that it is potentially salvageable.

            The flywheel would move just the slightest bit before I put the wrench on it, so likely just the rings rusted to the bore.

            Thanks for the advice.

            October 17, 2016 at 5:22 pm #46017
            20mercman
            Participant

              Those 350’s were a really good motor. Mercury built the power head for internal use, as they wanted a test mule for lower units, and found that they ran so well that they built a motor around it. If you ask many Mercury fans, they will often add the early 350 as one of Mercury’s best. I am glad to hear that you intend to pull it down. The thing to make sure of is that the needles in the connecting rods have not rusted. These are split case motors, so pulling them apart is fairly easy, and you would want to replace the crank seals anyway. Best of luck with your project!

              Steve

              October 17, 2016 at 9:43 pm #46025
              david-bartlett
              Participant

                Steve,

                Thanks for that information. I am also concerned about the condition of the needle bearings so I will look inside when I get the motor inside. I am still trying to get my West Bend Shark back together and I have a Super Fastwin strewn across the bench as well. I don’t need any more "in progress" at present.

                Oh yah, I have a second Water Witch in progress too. Too bad work gets in the way.

                David

              • Author
                Posts
              Viewing 6 posts - 1 through 6 (of 6 total)
              • You must be logged in to reply to this topic.