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  • Mercruiser turns over, doesn't start unless I pour gas in the carb...

    Hi everybody, new here from Kelowna, BC Canada, and looking for some advice.

    I recently inherited a late 90s 17' Maxum bowrider and with proper maintenance, I've had a few good seasons on her. It has a 3.0L Mercruiser Alpha One with Digital Electronic Ignition. I just pulled her out of storage and for some reason, she won't start. The situation:

    -The engine will turn over easily, and if I pour gas in the carb it will run briefly before it starves out and dies.
    -I'm getting fuel to the carb and it's under pressure (I disconnected the line briefly to check).
    -I noticed that when choking I don't smell fuel, and no fuel is visibly getting into the carb.

    I'm wondering if there is an issue with the choke or accelerator pump? Any advice or insight would be hugely appreciated. My apologies if this is a novice question! Learning as I go...

    Thanks for reading!
    Calvin
    Last edited by TwiceMyAge; May 21st, 2020, 10:12 PM.

  • #2
    Sounds like dirt in the carburetor or jet.
    Fuel in the bowl doesn't always translate to fuel getting from the bowl into the carb throat.

    If putting gas into the carb gets it going, I'd start there.
    -squib

    My 1996 Tracker Project https://forums.iboats.com/forum/boat...ebuild-project

    Comment


    • #3
      What year is the motor or even better what is the serial number?

      Need to check the fuel system

      Remove fuel filter and see if there is anything but clean gas. You may have the upside down filter and it will all spill out so have a container to catch

      Remove the fuel line going to the carb and place it in a container. Crank the motor over and see if any gas goes into the container. The fuel pump should push out a good bit of gas

      94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
      95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
      07 Seadoo GTX
      Merc Adults Only VP Adults Only
      G-Dad always said "First Liar doesn't stand a chance"

      Comment


      • #4
        I realize you said you don’t see fuel delivery thru the venturi’s but are you certain?
        I had a similar problem years back on my 7.4l on initial start up after winterization.
        My problem turned out to be ethanol gas absorbing way too much water over time. I had also put new gas on top of old gas and still didn’t fire up. I had the carb off many times and I’d see puddles of fuel in the intake manifold. I thought I had a carb just dumping fuel making too rich to fire up.
        I finally made an auxiliary, gravity fed source from a gallon jug, emptied the carb of old fuel then cranked. Within seconds it started and ran until I got tired of listening to it.
        dumping the old gas was a pain

        Comment


        • #5
          Originally posted by calvinlechner View Post
          Hi everybody, new here from Kelowna, BC Canada, and looking for some advice.

          I recently inherited a late 90s 17' Maxum bowrider and with proper maintenance, I've had a few good seasons on her. It has a 3.0L Mercruiser Alpha One with Digital Electronic Ignition. I just pulled her out of storage and for some reason, she won't start. The situation:

          -The engine will turn over easily, and if I pour gas in the carb it will run briefly before it starves out and dies.
          -I'm getting fuel to the carb and it's under pressure (I disconnected the line briefly to check).
          -I noticed that when choking I don't smell fuel, and no fuel is visibly getting into the carb.

          I'm wondering if there is an issue with the choke or accelerator pump? Any advice or insight would be hugely appreciated. My apologies if this is a novice question! Learning as I go...

          Thanks for reading!
          Calvin
          first, how are you starting it. be specific.

          this is a carburetor, so starting is is more like a 1975 truck and less than any car after 1980

          one to two full pumps of the throttle, press the throttle only button, move throttle to about 30%, then hit key

          second, if the carb has sat for more than a year, you may need to go thru the carb and clean it. this will require a carb rebuild kit and about 2 hours of your time.
          Cheesehead boating the Gulf Coast of FLA 27.51° N, 82.53° W

          1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - https://forums.iboats.com/forum/owner...988-rogue-2420

          Past Boats
          1970 Wooster Hellion - Merc 9.8
          2002 SeaRay 190BR - 5.0 - A1G2 - "Cheeseheads in Paradise"
          1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

          What’s behind you doesn’t matter.Enzo Ferrari

          Comment


          • #6
            Thanks for the feedback guys, I'll be checking it out this weekend.

            Alldodge, It's a 1997, and the serial is 0K179423.

            I have removed the line at that the carb and there's fuel, so there's something going on after that.

            I have experienced this same issue last spring, but eventually she fired up and ran perfectly all season.

            Thanks again for your help!

            Comment


            • #7
              I have removed the line at that the carb and there's fuel, so there's something going on after that.
              So motor turns over and fuel pumps out, so its not the pump.
              The carb is clogged up like Squibbly said

              This is your motor
              https://www.mercruiserparts.com/3-0l...-0l010042-thru
              94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
              95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
              07 Seadoo GTX
              Merc Adults Only VP Adults Only
              G-Dad always said "First Liar doesn't stand a chance"

              Comment


              • #8
                Originally posted by alldodge View Post

                So motor turns over and fuel pumps out, so its not the pump.
                The carb is clogged up like Squibbly said

                This is your motor
                https://www.mercruiserparts.com/3-0l...-0l010042-thru
                Even if the boat runs temporarily when I pour gas in the carb?

                Comment


                • #9
                  Originally posted by Scott Danforth View Post

                  first, how are you starting it. be specific.

                  this is a carburetor, so starting is is more like a 1975 truck and less than any car after 1980

                  one to two full pumps of the throttle, press the throttle only button, move throttle to about 30%, then hit key

                  second, if the carb has sat for more than a year, you may need to go thru the carb and clean it. this will require a carb rebuild kit and about 2 hours of your time.
                  That is more or less what I'm doing, although are you saying the first two pumps should be without the 'throttle only' engaged?

                  Comment


                  • #10
                    Originally posted by Squibbly View Post
                    Sounds like dirt in the carburetor or jet.
                    Fuel in the bowl doesn't always translate to fuel getting from the bowl into the carb throat.

                    If putting gas into the carb gets it going, I'd start there.
                    Thanks Squibbly. Sounds like everybody agrees. Any good resources for a carb rebuilt kit?

                    Comment


                    • #11
                      Having a Merc carb it will have a filter behind the large nut. Remove the nut and check the filter. If filter is plugged, depending on the replacement type will depend on how its installed

                      To get the correct carb kit, look for a tag on the carb with a number

                      Click image for larger version

Name:	Carb filter.jpg
Views:	4
Size:	71.8 KB
ID:	10869073
                      94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
                      95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
                      07 Seadoo GTX
                      Merc Adults Only VP Adults Only
                      G-Dad always said "First Liar doesn't stand a chance"

                      Comment


                      • #12
                        Hi guys, thanks for all your help. I decided to try some carb cleaner before rebuilding or taking anything apart. It was getting close but still no dice. A friend popped by and suggested I pour a bit of fuel in the little channel circled in red in the photo as well as the main part.

                        That did the trick and she ran strong!

                        What is that part called and any thoughts on why that worked?

                        Thanks again, happy to be seaworthy again.

                        C

                        Comment


                        • #13
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                          That's the float bowl vent, so your pouring fuel into the bowl. Will run until it uses the fuel up

                          The carb pic is for a TKS and you should have a Merc carb
                          94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
                          95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
                          07 Seadoo GTX
                          Merc Adults Only VP Adults Only
                          G-Dad always said "First Liar doesn't stand a chance"

                          Comment

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