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78 GS750E "No Spark"

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    78 GS750E "No Spark"

    I've replaced the Solenoid, Coils, Stator and now I'm afraid to try and start the bike.

    Reason 1. I bought 56 dollar coils from China/US distributor. The original OEM's tested at 1.0 and 1.2 resistance.

    The question I have is the original OEM coils had the spark plug wires coming out of the back of the coil in a top to bottom configuration.

    Meaning, from the rear of the bike looking to the front with the gas tank removed the left coil was for the 1 and 4 plug wires top and bottom respectively to the circumference.

    The right coil was the 2 and 3 plug wires, again top and bottom to the circumference.

    The new coils are left and right to the bottom of the circumference so I wired them 1,4 - 3,2.

    Is this correct?

    Thank you!
    1978 Suzuki GS 750 EC

    #2
    Don't see a problem there. The HT secondary winding is just a double-ended coil with each end feeding the plug leads.
    ---- Dave
    79 GS850N - Might be a trike soon.
    80 GS850T Single HIF38 S.U. SH775, Tow bar, Pantera II. Gnarly workhorse & daily driver.
    79 XS650SE - Pragmatic Ratter - goes better than a manky old twin should.
    92 XJ900F - Fairly Stock, for now.

    Only a dog knows why a motorcyclist sticks his head out of a car window

    Comment


      #3
      Thanks Grimly!! I was worried the 3,2 needed to be 2,3. I'm a novice at best!
      1978 Suzuki GS 750 EC

      Comment


        #4
        Originally posted by Grimly View Post
        Don't see a problem there. The HT secondary winding is just a double-ended coil with each end feeding the plug leads.
        Thank you!!

        One last thing I have is the stator. The OEM stator had 3 wires coming out of the sleeve, one of which had a double female connector. The new one only had 3 wires with 3 female connectors so I cut the double female connector off the dead stator and wired it to one of the 3 wires on the new stator. Is this kosher?
        1978 Suzuki GS 750 EC

        Comment


          #5
          Originally posted by Shred Astaire View Post
          Thank you!!

          One last thing I have is the stator. The OEM stator had 3 wires coming out of the sleeve, one of which had a double female connector. The new one only had 3 wires with 3 female connectors so I cut the double female connector off the dead stator and wired it to one of the 3 wires on the new stator. Is this kosher?
          No, It does not. 3 Stator wires should remain separate and go into 3 separate wires on your R/R. Or, does your bike have separate regulator and rectifier. Either way, Since you've gone through the expense of new coils, stator, solenoid, go ahead and update the R/R to a modern series type like the Shindengen SH775 or Compufire. Your charging system will thank you.
          Rich
          1982 GS 750TZ
          2015 Triumph Tiger 1200

          BikeCliff's / Charging System Sorted / Posting Pics
          Destroy-Rebuild 750T/ Destroy-Rebuild part deux

          Comment


            #6
            I would have hard wired (solder/crimp) the stator to the wire harness. No additional connectors between the stator and the R/R.

            1980 GS1000GT (Daily rider with a 1983 1100G engine)
            1998 Honda ST1100 (Daily long distance rider)
            1982 GS850GLZ (Daily rider when the weather is crap)

            Darn, with so many daily riders it's hard to decide which one to jump on next.

            JTGS850GL aka Julius

            GS Resource Greetings

            Comment


              #7
              Originally posted by Rich82GS750TZ View Post
              No, It does not. 3 Stator wires should remain separate and go into 3 separate wires on your R/R. Or, does your bike have separate regulator and rectifier. Either way, Since you've gone through the expense of new coils, stator, solenoid, go ahead and update the R/R to a modern series type like the Shindengen SH775 or Compufire. Your charging system will thank you.
              It is because there is a separate regulator bolted to the bottom of the battery box.
              1978 Suzuki GS 750 EC

              Comment


                #8
                Originally posted by JTGS850GL View Post
                I would have hard wired (solder/crimp) the stator to the wire harness. No additional connectors between the stator and the R/R.
                I don't have enough knowledge or soldering skills to do that. Thank you for the reply!!
                1978 Suzuki GS 750 EC

                Comment


                  #9
                  Originally posted by Shred Astaire View Post
                  It is because there is a separate regulator bolted to the bottom of the battery box.
                  I stand by my previous statement. You've thrown a bunch of new parts at it. Throw on 1 more that has been proven to fix/improve the health of the charging system. An SH775 ($40-$50 used on ebay) and a $10-12 connector kit from Triumph for the SH775 (part number alludes me but it's very common). Your new stator is not likely to last very long if you continue to use the stock regulator and rectifier.
                  Rich
                  1982 GS 750TZ
                  2015 Triumph Tiger 1200

                  BikeCliff's / Charging System Sorted / Posting Pics
                  Destroy-Rebuild 750T/ Destroy-Rebuild part deux

                  Comment


                    #10
                    Originally posted by Rich82GS750TZ View Post
                    I stand by my previous statement. You've thrown a bunch of new parts at it. Throw on 1 more that has been proven to fix/improve the health of the charging system. An SH775 ($40-$50 used on ebay) and a $10-12 connector kit from Triumph for the SH775 (part number alludes me but it's very common). Your new stator is not likely to last very long if you continue to use the stock regulator and rectifier.
                    Already looking into it Rich! Thanks for the heads up. Any links would be great too. It appears that all the knockoffs use that part number too so I'm trying to find the source supplier of my make, model and year.
                    1978 Suzuki GS 750 EC

                    Comment


                      #11
                      Here's one for $79 new. https://www.ebay.com/itm/Polaris-401...MAAOSwtilb5jpn

                      Important feature in the printing in white on the top fin. It must say SH775AA (I think the other variant is SH775BA ??, but there's no difference). If it doesn't have that, it's not genuine. If you have doubt, post a pic of it here and someone will let you know if it's real or not. You do not want a knock off. I didn't see any used ones but didn't look long.

                      The Triumph connector is T2500676

                      On the triumph connector you would keep the ends that plug in to the SH775. Cut off the other end. Opinions vary on the connection of choice for connection the red wire to your harness and the 3 wires off the other side to your stator. Black that's on the same side as the red goes to ground.

                      Nessism did a nice diagram to show the connection very simply. He also buys use SH775s, tests them and resells them to members at a good price. Hit him up and see if he's got any.
                      Last edited by Rich82GS750TZ; 05-26-2020, 12:15 PM.
                      Rich
                      1982 GS 750TZ
                      2015 Triumph Tiger 1200

                      BikeCliff's / Charging System Sorted / Posting Pics
                      Destroy-Rebuild 750T/ Destroy-Rebuild part deux

                      Comment


                        #12
                        Originally posted by Rich82GS750TZ View Post
                        Here's one for $79 new. https://www.ebay.com/itm/Polaris-401...MAAOSwtilb5jpn

                        Important feature in the printing in white on the top fin. It must say SH775AA (I think the other variant is SH775BA ??, but there's no difference). If it doesn't have that, it's not genuine. If you have doubt, post a pic of it here and someone will let you know if it's real or not. You do not want a knock off. I didn't see any used ones but didn't look long.

                        The Triumph connector is T2500676
                        That's great Rich. I'm on it. Thank you!!

                        Thanks everyone for the help!!!
                        1978 Suzuki GS 750 EC

                        Comment


                          #13
                          Contact member Nessism on the forum. He sells used SH775 R/R's that he has tested to ensure they work correctly. It is a series type combined regulator and rectifier with 3 input wires from the stator, a positive output wire, and an earth (ground) wire.

                          The series R/R is much kinder to your stator than the OEM shunt type. Read all about it in posts by member Posplayr.

                          The earlier Suzuki's had a separate regulator and separate rectifier, but later models all had the combined regulator/rectifier.

                          The part number for the Triumph connector lead is T2500676.
                          1981 GS850G "Blue Magic" (Bike Of The Month April 2009)

                          1981 GS1000G "Leo" (Bike Of The Month August 2023)

                          Comment


                            #14
                            The SH775AA will have Seadoo part #710001103 on it. The SH775BA will have Polaris part #4012941.

                            Here's a used one for $35 shipped. https://www.ebay.com/itm/Polaris-Reg...0/303341885592
                            Jordan

                            1977 Suzuki GS750 (My first bike)
                            2000 Kawasaki ZRX1100
                            1973 BMW R75/5

                            Comment


                              #15
                              Buy the one Jordan posted. Probably will not find cheaper.

                              edit: Ad says it’s a stock image. Maybe hold off unless seller can confirm with a pic of the actual top fin with the white lettering.
                              Last edited by Rich82GS750TZ; 05-26-2020, 03:49 PM.
                              Rich
                              1982 GS 750TZ
                              2015 Triumph Tiger 1200

                              BikeCliff's / Charging System Sorted / Posting Pics
                              Destroy-Rebuild 750T/ Destroy-Rebuild part deux

                              Comment

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