Announcement

Collapse
No announcement yet.

Mercarb choke not working

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

    Mercarb choke not working

    hi all, today when I went to start the boat it kept winding over but wouldn’t fire. I did some quick investigation and she’s getting fuel and spark but the choke doesn’t close when I turn the key. So I’m wondering what would cause the choke to not work. Am I right that on a cold engine, when you turn the key and give power that the choke butterfly should close?
    thanks for any help, Nick

    5.0 litre carby motor
    2004 245 Cierra Alpha one Gen II "Sabre II"
    2004 505 Windstorm Yamaha 90hp "Sabre One"

    #2
    If it's an electric choke and the engine is "cold" it'll default to the choked position (closed or close to it) untill the key has been turned to the "run" position, at that point the choke plate will begin to open.
    Dave
    Edmonds, WA
    "THE FIX"
    '93 2556
    Carbureted 383 Vortec-Bravo II 2.0:1 18 1/4x19 P

    The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
    Misc. projects thread
    https://www.baylinerownersclub.org/f...56-gctid789773

    Comment


      #3
      If you advance the throttle beyond idle does the choke plate move freely?
      1997 Maxum 2400 SCR 5.7LX Bravo II

      Mike

      Comment


        #4
        Try advanceing the throttle fully, if the choke doesn't open post back.

        woa came back to edit ...

        could this his be a Tks carb ?

        if yes, solenoid sticking.
        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


          #5
          Check that it’s moving freely, grab and wiggle it back-and-forth. When you look at it full cold it should be almost fully closed. If yours is like mine which I think it is that big Disk on the the side of the carburetor held on by three screws is nothing but a coil spring in there that reacts to temperature. You adjust the spring tension by loosening something( brain fart) and turning the disk which moves the chokeas well. iIRC When it’s cold and the choke is closed you should be just able to slide a 1/8th inch drill bit in and out of the crack. That’s basically the adjustment setting and the spring does all the rest.
          I did have mine freeze up one time from the alcohol gas and welded that cross pivot right into the body of the carburetor. Cold starts were a real pain before I figured it out and it was a beast to get it off of there. I even had to drill the corrosion out of the holes and you don’t want to go there Because realistically you have to take the carb off the boat. Probably wouldn’t hurt to put a shot of spray oil on both sides every year to keep that sort of thing from occurring.
          If you can , try putting a hairdryer on that drisk and just see what happens. It should slowly open fully up in a short bit as the spring inside the disc unwinds. That will tell you it’s working as it should.

          Comment


            #6
            We forget that a part of yearly maintenance when we all had cars with carbs was to clean the choke shaft, plate and linkage with carb cleaner once a year. Those thermostatic springs are not very stiff and it does not take much to make them stick.
            88 Four Winns 200 Horizon 4.3 OMC
            98 Jeep Grand Cherokee 4.0/Selectrac
            07 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

            Long Island Sound Region

            Comment


              #7
              Choke moves freely when throttle is moved. Choke plate isn’t closed on cold engine. I took the flame arrester off and when I turn the key the choke plate sits at about 1/3 closed.

              Pretty sure not tks. It has the disc on the side held on by three screws as driz says.

              When I wiggle the choke plate by hand it moves freely. The problem is I won’t close when cold. Seems weird that it would throw itself out of adjustment so far by itself.
              2004 245 Cierra Alpha one Gen II "Sabre II"
              2004 505 Windstorm Yamaha 90hp "Sabre One"

              Comment


                #8
                So do you reckon I should undo those three screws on the disc and spray some carby cleaner in there. Is that where the spring is housed?

                Will removing that disc disc screw up my choke adjustment?
                2004 245 Cierra Alpha one Gen II "Sabre II"
                2004 505 Windstorm Yamaha 90hp "Sabre One"

                Comment


                  #9
                  This is what mine looks like. I don’t see a spring?
                  2004 245 Cierra Alpha one Gen II "Sabre II"
                  2004 505 Windstorm Yamaha 90hp "Sabre One"

                  Comment


                    #10
                    On a cold engine, Loosen the three screws and rotate the housing until the choke is about 1/4" away from fully closed then snug down the screws. Next turn the key to run position (verify 12 volts at the electrical connections at the choke) and watch the choke plate, it should go full open in about a minute or so. If it doesn't move the thermostatic spring could have failed/broke.
                    Dave
                    Edmonds, WA
                    "THE FIX"
                    '93 2556
                    Carbureted 383 Vortec-Bravo II 2.0:1 18 1/4x19 P

                    The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                    Misc. projects thread
                    https://www.baylinerownersclub.org/f...56-gctid789773

                    Comment


                      #11
                      K heading down to the boat soon. I’ll give it a try. Thanks

                      just in case it is the spring broke, where is it located so I can check it?
                      2004 245 Cierra Alpha one Gen II "Sabre II"
                      2004 505 Windstorm Yamaha 90hp "Sabre One"

                      Comment


                        #12
                        Thermostatic coil (spring) is inside the electric choke housing. Also double check that all choke linkage can move freely.
                        Dave
                        Edmonds, WA
                        "THE FIX"
                        '93 2556
                        Carbureted 383 Vortec-Bravo II 2.0:1 18 1/4x19 P

                        The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                        Misc. projects thread
                        https://www.baylinerownersclub.org/f...56-gctid789773

                        Comment


                          #13
                          I agree with what Dave is telling you. However you should be able to start the boat by keeping the throttle advanced with the shifter disengaged. Even at idle it should start then die with a bad choke.
                          1997 Maxum 2400 SCR 5.7LX Bravo II

                          Mike

                          Comment


                            #14
                            Thanks guys for your help. Went down there today and it fired up straight away. I think I just flooded the crap out of it yesterday and because I had the key on for a while the choke was remaining open. It was closed when I first got there this morning. My bad. I feel like a dick. But on the up side she’s working for my Chrissy holiday!!!
                            2004 245 Cierra Alpha one Gen II "Sabre II"
                            2004 505 Windstorm Yamaha 90hp "Sabre One"

                            Comment


                              #15
                              Glad she’s up and running. Don’t feel bad just enjoy her.
                              1997 Maxum 2400 SCR 5.7LX Bravo II

                              Mike

                              Comment

                              Working...
                              X