Announcement

Collapse
No announcement yet.

Engine Popping/Backfiring

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
    #1

    Engine Popping/Backfiring

    Hello all,

    I have a 1996 Tige with a 350 Magnum Tournament Ski engine. I live in South Texas so I have been taking it on the lake every week until mid-January and there has been no problems. I replaced the starter and changed the oil after the last session. The boat took about a month off, then I took her on the lake again this last Monday.

    When I accelerated, there was backfiring/popping coming from the carb area. If the boat is in neutral, the engine RPM's can get up to 4800 RPM no problem, but once there is a load on the engine, the problems start. Today, I took the spark plugs out and cleaned them a bit, but they did not seem that dirty. I also took the carb off and I am going to clean that tomorrow.

    I did a search of this problem and many people say it is the computer and/or a lose ground. I did disconnect the battery when I changed the starter, but it is secure now. Does this 96 carb engine even have a computer? Thanks in advance for your help.
    Tags: backfiring, carb, engine, popping
    #2
    Originally posted by bagzzz View Post
    Hello all,

    I have a 1996 Tige with a 350 Magnum Tournament Ski engine. I live in South Texas so I have been taking it on the lake every week until mid-January and there has been no problems. I replaced the starter and changed the oil after the last session. The boat took about a month off, then I took her on the lake again this last Monday.

    When I accelerated, there was backfiring/popping coming from the carb area. If the boat is in neutral, the engine RPM's can get up to 4800 RPM no problem, but once there is a load on the engine, the problems start. Today, I took the spark plugs out and cleaned them a bit, but they did not seem that dirty. I also took the carb off and I am going to clean that tomorrow.

    I did a search of this problem and many people say it is the computer and/or a lose ground. I did disconnect the battery when I changed the starter, but it is secure now. Does this 96 carb engine even have a computer? Thanks in advance for your help.
    What kind of gas are you putting in it? I you used a gas with any ethanol in it, it attracts moisture. This occurs when it sits for a period of time in the tank and the gas absorbs moisture. This makes the engine run rough and eventually cause motor damage. The easiest way to fix this is to put stabil fuel additive in the tank and use 100% ethanol free gas.

    Comment

      #3
      The other thing to check is the condition of your plug wires. Ski boats run at higher RPMS so you almost have to replace the plug wires as often as the plugs (every 400 hours or so).
      Cursed by a fortune cookie: "Your principles mean more to you than any money or success."

      Comment

        #4
        Originally posted by goose69 View Post
        What kind of gas are you putting in it? I you used a gas with any ethanol in it, it attracts moisture. This occurs when it sits for a period of time in the tank and the gas absorbs moisture. This makes the engine run rough and eventually cause motor damage. The easiest way to fix this is to put stabil fuel additive in the tank and use 100% ethanol free gas.
        I live on an Air Force Base, so I put AAFES gas in. Not sure the quality of that gas. I will put stabil in before I fire it up again.

        Comment

          #5
          Originally posted by dogbert View Post
          The other thing to check is the condition of your plug wires. Ski boats run at higher RPMS so you almost have to replace the plug wires as often as the plugs (every 400 hours or so).
          I changed the spark plugs and wires last May. I dont think I have put 400 hours on it since then, but that could be a possibility. I use the boat 3 times a week...

          Comment

            #6
            Originally posted by bagzzz View Post
            I changed the spark plugs and wires last May. I dont think I have put 400 hours on it since then, but that could be a possibility. I use the boat 3 times a week...
            On older Mercruisers the distributor cap is a real PITA. I'd check that and change it.
            Cursed by a fortune cookie: "Your principles mean more to you than any money or success."

            Comment

              #7
              I noticed the ethanol issue came up again. I've notice around us most of the gas stations have ethanol in the gas. I am not sure which stations don't. I have been putting in Marine Stabil each tank full. Will this help me w/ the ethanol problem, I have had the same issues as bagzzz from time to time. If I remember right I ran all the gas out and then changed all my plugs and wires and I haven't had any issues last year.
              Last edited by TRD; 02-25-2010, 03:32 PM.
              Dale
              2000 21i Tige

              Comment

                #8
                I agree with Dog on the Distributor cap. Triple check it. The fuel is suspect as well?
                Mike Allen, Tigé owner since 1997

                Comment

                  #9
                  Originally posted by TeamAllen View Post
                  I agree with Dog on the Distributor cap. Triple check it. The fuel is suspect as well?
                  I had that problem and mine was fuel. I found a station that sells ethanol free gas and 20hrs later still no problem. Ethanol gas is about 8 cents a gallon more, but your will see your useage go down. I burn 3.5-4 gallons an hour @ 22mph using ethanol free gas

                  Comment

                    #10
                    In my experience, most of the time, backfiring is caused by an ignition primary (module and pickup) or ignition secondary (plugs, wires, cap, rotor) component. But nothing should be left out, just start with whats cheap and easy to fix first.
                    Mikes Liquid Audio: Knowledge Experience Customer Service you can trust-KICKER WetSounds ACME props FlyHigh Custom Ballast Clarion LiquidLumens LEDs Roswell Wave Deflector And More

                    Comment

                      #11
                      I have to replace plugs, wires, etc this year. Must I use Marine Wires, etc or just high quality auto parts?

                      Comment

                        #12
                        Originally posted by laserfish View Post
                        I have to replace plugs, wires, etc this year. Must I use Marine Wires, etc or just high quality auto parts?
                        Automotive parts, regardless of quality, are not ignition protected, especially distributor caps. Best practice is to always use marine grade fuel and ignition/electrical components
                        Mikes Liquid Audio: Knowledge Experience Customer Service you can trust-KICKER WetSounds ACME props FlyHigh Custom Ballast Clarion LiquidLumens LEDs Roswell Wave Deflector And More

                        Comment

                          #13
                          back...

                          Ok, 3 weeks ago, I took the boat out again to test it after I changed the distributor cap and rotor. They needed to be replaced. The boat performed a little better, but not much. Because my boat was not working, I went skiing behind my buddy's boat and ended up shattering my ankle. I will be on crutches for another 5 weeks... That is why I have not been back to comment for a while.

                          After all the talk about the gas, I siphoned all the old gas out and put a fresh tank in with some mercury fuel system cleaner and some B12. I also changed the water separating fuel filter (there was some nasty stuff that came out of the filter). I also replaced all the plugs, thinking that could be the case. I fired her up again to find that my impeller was no-more and I had to replace that too. After changing the impeller and firing up the engine, the same problem still exists.

                          I decided to check the timing, and these are the results (see picture for reference):

                          IMG_0279.jpg

                          600 RPM - at the T in BTDC
                          800 RPM - 12 degrees
                          1000 RPM - 12 degrees
                          1500 RPM - at the B
                          2000 RPM - at the D

                          I am pretty sure this timing is off, but I have no idea how to fix it. I have thunderbolt V ignition, so shouldn't that automatically fix it? I am not sure where the adjustment is.

                          To see exactly what my engine is doing, check out this video. The first part is showing how when I ease the throttle forward, it runs nice. The rest of the video shows when I add full throttle, it starts to cough. Sorry the quality is pretty bad, I took it with my iPhone...

                          Comment

                            #14
                            http://www.youtube.com/watch?v=OqqIzVxCC5E

                            Comment

                              #15

                              Comment

                              Previous 1 2 template Next
                              Working...
                              X