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Tat timing for 5.7 350 2bbl yr 2000-gctid384833

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    Tat timing for 5.7 350 2bbl yr 2000-gctid384833

    what should the TAT ( total advanced timing ) be for a year 2000 5.7L 350 2BBL

    mercruser be ? i believe it should be 10 deg at idle but im not sure of the

    TAT and at what rpm.

    Thank you in advance

    #2
    Merc shows quite a few different curves for their V-8's. Be sure you see the correct one.

    Also, look in the BOC Library for links to Merc info.

    http://www.boatfix.com/merc/Techbk/95/95HGB4.PDF
    Rick E. Gresham, Oregon
    2850 Bounty Sedan Flybridge model
    Twin 280 HP 5.7's w/ Closed Cooling
    Volvo Penta DuoProp Drives
    Kohler 4 CZ Gen Set

    Comment


      #3
      Thank you Rick !! i dont believe i have the thunderbolt ignition though

      i dont see anything non thunderbolt in the link you sent.

      Attached files [img]/media/kunena/attachments/vb/688467=28070-Photo0526.jpg[/img]

      Comment


        #4
        You have thrunderbolt Vs in that boat depicted. Thats those thingies mounted on the inside of the port side exhaust manifolds. Don't even think about trying to "power time" it.

        Thr T-bolt V is a very complicated microprocessor based ignition/timing system. This allows 250 HP out of a 2 BBL carb, where it was 220 HP with the t-bolt V. There is also a comperable fuel saving at all RPMs.

        The procedure is:

        1. Buy a manual before screwing with the engine. Improper setting can burn a hole thru the piston tops.

        2. Disable the knock sensor by grounding the purple-white wire to the starboard of the carburator.

        Set the timing to the spec at idle (650RPM). Remove ground, Do not screw with the timing, as the knock module compensates for all conditions, 6 times a second.

        No personal attack intended, but I have seen an engine where the owner tried to outsmart the microprocesser. The timing went way high, and burned completely thru #4, #7, and #8 pistons in a 2 hour run. He had to get a new long block.
        Captharv 2001 2452
        "When the draft of your boat exceeds the depth of water, you are aground"

        Comment


          #5
          I agree with Harv. Set BASE or Initial, and let the system do what it's suppose to do.

          However, this does not prevent you from looking and checking to see where the progressive and TA are..... and I suppose that's why you asked for an advance curve!

          Now.... perhaps someone changed this from the Merc TB system. For this, we'd need a few good photos of the ignition distributors.

          Or.... you pull a distributor cap and see if you can rotate the rotor.
          • If it rotates approximately 10*, you'll have a mechanical advance system that was changed out by someone.
          • If it acts ridged and does not rotate, then you have an EST system...... (i.e., the Merc TB, or Delco, or ????)




          .
          Rick E. Gresham, Oregon
          2850 Bounty Sedan Flybridge model
          Twin 280 HP 5.7's w/ Closed Cooling
          Volvo Penta DuoProp Drives
          Kohler 4 CZ Gen Set

          Comment


            #6
            thank you Bounty and Captharv

            i just installed a new coil,dist cap,rotor and plugs last night my motor idles way better now.IM still confused about which

            ignition i have though.Captharv says T-BOLT 5 . QUOTE BY Captharv..

            " Thr T-bolt V is a very complicated microprocessor based ignition/timing system. This allows 250 HP out of a 2 BBL carb, where it was 220 HP with the t-bolt V " This sentace does not make sense to me, it says T-BOLT V twice

            i just got off the phone with the merc dealership and they said because the module is mounted on the side of the riser its a T-BOLT 4

            i really need to know which one it is because they are two different base timing set ups.

            i really dont want to doubt anyone on this board but i am getting coflicting information

            i have attatched a older pic of my motor where you can see the module better

            port motor ser# M018153 starb motor ser# M010718

            thanks again guys.

            Attached files [img]/media/kunena/attachments/vb/688698=28100-dist cap new.jpg[/img] [img]/media/kunena/attachments/vb/688698=28099-dist cap old.jpg[/img] [img]/media/kunena/attachments/vb/688698=28098-motor dirty.jpg[/img]

            Comment


              #7
              seadaemon wrote:


              i really dont want to doubt anyone on this board but i am getting coflicting information

              i have attatched a older pic of my motor where you can see the module better

              port motor ser# M018153 starb motor ser# M010718
              What and who is giving you conficting information?

              The controller on your Port side manifold highly suggests the Merc EST...... Merc TB Ignition! (EST = electronic spark timing)

              Shosrt of that, the simplest method to know for certain, is to do the following:

              2850Bounty wrote:
              you pull a distributor cap and see if you can rotate the rotor.
              • If it rotates approximately 10*, you'll have a mechanical advance system that was changed out by someone.
              • If it acts ridged and does not rotate, then you have an EST system...... (i.e., the Merc TB, or Delco, or ????)



              Rick E. Gresham, Oregon
              2850 Bounty Sedan Flybridge model
              Twin 280 HP 5.7's w/ Closed Cooling
              Volvo Penta DuoProp Drives
              Kohler 4 CZ Gen Set

              Comment


                #8
                Rick..I undertand,but can you tell me if it is the thunderbolt 4 or the thunderbolt 5 ?

                the merc dealer says T-bolt 4 and Captharv says T-bolt 5 both have differnt ways to set the base timing

                Comment


                  #9
                  I believe that the actual distributor may be the same, but the module should state TB IV or TB V. Yes/No????
                  Rick E. Gresham, Oregon
                  2850 Bounty Sedan Flybridge model
                  Twin 280 HP 5.7's w/ Closed Cooling
                  Volvo Penta DuoProp Drives
                  Kohler 4 CZ Gen Set

                  Comment


                    #10
                    RICK...IM not sure,i will have to look when i get down to the boat tonight

                    i will take a bunch of pics

                    thanks for your help so far.

                    Comment


                      #11
                      one more time......

                      The mercruiser ignition systems are as such:

                      The t-bolt IV has one module on the inside of the port manifold.

                      The t-bolt V has 2 modules, piggbacked on the inside of the port manifold.

                      The difference is the above mentioned knock module, which is the smaller of the 2 whbich are piggybacked.

                      Note: This is a biggie: If your mechanic does not know the difference between a IV and a V ignition, I would not let him touch my boat. Get a merc certified mechanic.

                      We engineers have a saying: "If you don't know what it does, don't screw with it"
                      Captharv 2001 2452
                      "When the draft of your boat exceeds the depth of water, you are aground"

                      Comment


                        #12
                        Look at 4B-5 here for the TB V (DESA). That should help you identify which system you have. It also confirms that the distributors are the same.

                        However, according to this page, the TB V knock sensor module is also mounted on the distributor.

                        Perhaps there are several versions of this whereby the modules are mounted on the manifold.

                        I agree with Harv. If you are not comfortable in doing this, seek the help of someone who is certified.

                        .
                        Rick E. Gresham, Oregon
                        2850 Bounty Sedan Flybridge model
                        Twin 280 HP 5.7's w/ Closed Cooling
                        Volvo Penta DuoProp Drives
                        Kohler 4 CZ Gen Set

                        Comment


                          #13
                          Captharv and Bounty i have attatched more pics to try and figure out if my ignition system

                          is the T-BOLT 4 or T-BOLT 5. My dealership still says T-BOLT 4 but from what Captharv says

                          i believe it is a T-BOLT 5.

                          Thanks again guys

                          Attached files [img]/media/kunena/attachments/vb/689741=28203-DIST 2.jpg[/img] [img]/media/kunena/attachments/vb/689741=28204-ENGINE 1.jpg[/img] [img]/media/kunena/attachments/vb/689741=28201-T-BOLT 1.jpg[/img] [img]/media/kunena/attachments/vb/689741=28202-T-BOLT 2.jpg[/img]

                          Comment


                            #14
                            Rick....just looking at the pages from the electrical systems you sent

                            i cannot find the inital base timing for the T-BOLT 5 on my 5.7 L ,only the T-BOLT 4

                            the last page does show a T-BOLT 5 spark control graph.Would it be safe

                            to assume the initail timing is 8 DEG BTDC timed by jumping out the PUP/WHT

                            lead to ground and using a timing light.

                            Comment

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