1974 Evinrude Yachtwin 4hp – failing to start

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  • August 1, 2015 at 2:21 am #2165
    jay
    Participant

      US Member

      I have a 74 4hp yachtwin that is not starting. In fact I get no kick at all when I pull it over. There is spark, and the plugs seem wetish as if fuel is getting through. Suggestions on which direction to check first?

      Thanks again
      Jay

      August 1, 2015 at 6:55 am #21362
      legendre
      Participant

        First off, check compression – that’s just standard drill.

        If you don’t have a tester, then pull the plugs, put your thumb firmly over one plug hole, and have someone pull the recoil once or twice. If the motor promptly blows your finger off the plug hole, then move to the other cylinder. If both blow your thumb off the hole, then you probably have enough compression to run it.

        Not enough compression to blow your finger off? Then look for compression leaking issues in the power head.

        August 1, 2015 at 10:31 am #21363
        billw
        Participant

          US Member

          Well, if what you say is true, with good spark and wettish plugs, then I would make sure the plug wires are on the right plugs. That’s an easy mistake to make and easier to fix. There SHOULD be a small identification band on the wire for the top plug. Also, do NOT try to start it where it says, "start." Start it on "FAST."

          If that’s not it, then you’re back to compression and making doubly sure it has GOOD spark. The spark should be able to jump 3/16" at least.

          Was the engine running recently? It would be a rare event if you pulled an engine out that has sat for ten years or more and it started just like that.

          Long live American manufacturing!

          August 1, 2015 at 12:05 pm #21369
          jay
          Participant

            US Member

            I’ll check the spark plug wires and run a compression test.

            There was some history here on the old boards of this motor, but its gone now, so I will recap.

            I got this motor with a sailboat I bought some time ago. It’s probably the one motor that got me involved in the old outboards as I started getting advice here. Anyhow, I got the motor in Connecticut, and brought it to Florida (Port Charlotte) with the sailboat. Didn’t realize how shallow Charlotte Harbor can be in places and promptly ran it into the ground, breaking shear pins etc. Got the motor repaired down there and brought it home.

            After consultation with the fine members of AOMCI I got the motor running again, but on open water tests it was overheating badly. General advice was that there was probably something jamming the water passages in the head, and a head removal/cleanout was in order. I did this, and did find a few passages that were blocked with dried mud/salt. I cleaned the passages and put the motor back together.

            I’m pretty sure I ran the motor in a barrel at home, just a quick startup. But this was a year ago +. I do know that when I put the coil start puller back together, it now seems to pull and retrieve somewhat slower. I tried pulling the motor over with a rope on top as it was spinning it faster then, but no luck.

            So, Ill check the plug wires and the compression and may pull the flywheel to look at the points and check them. See if I can get her popping over again. Ill let you know.

            August 1, 2015 at 1:25 pm #21375
            fleetwin
            Participant

              US Member

              OK, I remember this discussion from the past. I guess it would be good to know if you actually had the engine running after you had the head/exhaust cover off. You say the plugs appear wet, please be sure they are not wet with water. If the compression is OK, try pumping a little fuel oil mix into each cylinder.
              You can fish the starter rope around the pulley an extra time or two without disassembly to tighten up spring tension if needed, trying to start that engine with the rope wrapped around the flywheel will be a struggle!
              No need to pull the flywheel if the spark will jump a 1/4" gap, just be sure the leads are on the right plugs!

              August 3, 2015 at 1:33 pm #21483
              bob
              Participant

                Did you replace the cylinder head gasket with a new one when you reassembled your motor?If not,then low compression is probably your problem as stated above.

                August 3, 2015 at 5:22 pm #21493
                jay
                Participant

                  US Member

                  Minor update – I pulled the motor over with some starting fluid and it ran shortly, couldn’t get it to keep going on the fuel from the can though.

                  I’m going to pull the flywheel shortly and make sure the timing is set ok with Franks timing tool, to check that.

                  I think there is gunk in the carb and that may be the issue. Does anyone know if the carb can be removed without removing the powerhead? It looks like if I pull the high and low speed needles out I might be able to finagle the carb out of there? Anyone know if thats not true.

                  Bob, I did replace the gasket when I had the head off, that I do remember. Thank you for the note though, so many things can be the issue.

                  I’m think I recall taking the motor out and running it last year and then it had some issue with the recoil starter (i seem to recall that I left the bolt too loose and it was coming apart) So I took the motor home and tightened it up with FULL intention of running it again. I’m guessing I never drained the gas and it sat for a year with gas that is now more akin to sterno than unleaded.

                  Ill report back regarding the timing in a bit.

                  Jay

                  August 3, 2015 at 5:28 pm #21495
                  willyboy
                  Participant

                    yes you can get the carb off without taking the powerhead off,i am working on the same engine right now. Coils,points,condensers,carb rebuild.

                    August 3, 2015 at 5:30 pm #21496
                    willyboy
                    Participant

                      Forgot,i got mine out without taking the hi/low needles out by turning it sideways towards the recoil and sliding it out-tight fit but it’ll come out.

                      August 3, 2015 at 6:51 pm #21499
                      fleetwin
                      Participant

                        US Member

                        You could start by just removing the high speed needle and having a look at what drains out of the carb along with how the high speed needle looks. If smelly goo dribbles out and the high speed needle is gunky green, then yes, you will have to pull the carb.
                        Try connecting the fuel line and pumping it with the high speed needle removed, fuel should dribble out of the carb while pumping the primer bulb. The inlet needle is stuck if fuel does not come out of the carb while priming with the high speed needle removed.
                        In any event, the initial settings for the needles are: .75 turns out from gently seated for the high speed needle/1.5 turns out for the low speed needle.
                        You mentioned the plugs look wet, perhaps the fuel in the tank is old/fouled/has water in it.
                        Nonetheless, the carb comes out without removing the needles. Simply pull the carb forward off its mounting studs, then tilt the back up over the studs and back the carb on out of the pan.

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