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    New Project: 78 GS750

    So today I went and picked up my bike, a 1978 GS750. Eventually I plan on doing some light modifications both for appearance and performance so I figured I may as well start a build thread for the bike. But first I want to start with some maintenance items here's what I've found from my 10 mile ride home with the bike and the associated questions:

    Front tire - needs replacement due to the early stages of age cracks, thinking of going with the Dunlop D404
    Check brakes front and rear/new fluid
    Clutch - has an extremely hard pull to it. Is it common to put aftermarket springs in these bikes? Also which cover is for the adjuster?
    Oil change
    Front brake light switch doesn't work - has a non factory master cylinder so unsure of where to start on this
    Headlight side adjustment screw is missing
    Clean & lube chain
    Very extreme handle bar shake at certain speeds if I let go of it
    Mount tank - What is supposed to be there? See picture
    Fix original fuel petcock - The previous owner said it didn't work, and there's an inline aftermarket petcock, are the original ones still available?
    New plugs, check timing - possibly new points
    Lube all cables

    Anything I'm missing in the list that you think should be done? Once I complete the list I'm going to move on to replacing/repainting parts that have rust on them.
    Attached Files
    The current garage:
    1978 GS750
    1975 GT750M
    1984 CB700SC
    1982 XJ650 Seca Turbo
    1975 RD250 - 350 conversion

    #2
    Gas tank mount

    20170415_212606.jpgThis is the picture of the gas tank mounting bolt. Obviously there should be something else here but what is it?
    The current garage:
    1978 GS750
    1975 GT750M
    1984 CB700SC
    1982 XJ650 Seca Turbo
    1975 RD250 - 350 conversion

    Comment


      #3
      Subscribed!


      Ed
      GS750TZ V&H/4-1, Progressive Shocks, Rebuilt MC/braided line, Tarozzi Stabilizer[Seq#2312]
      GS750TZ Parts Bike [Seq#6036]
      GSX-R750Y (Sold)

      my opinion shouldn't be taken as gospel or in any way that would lead you to believe otherwise (30Sep2021)
      Originally posted by GSXR7ED
      Forums are pretty much unrecognizable conversations; simply because it's a smorgasbord of feedback...from people we don't know. It's not too difficult to ignore the things that need to be bypassed.

      Comment


        #4
        Follow the clutch cable down to a small cover on the left side. The tank parts you need are a couple of rubber cushions and a steel spacer. Fiche is your friend.

        Shop our large selection of Suzuki OEM parts, original equipment manufacturer parts and more online or call at (231)737-4542
        K.

        1978 GS750E
        1981 KZ440D

        Comment


          #5
          Originally posted by The1970's View Post
          So today I went and picked up my bike, a 1978 GS750. Eventually I plan on doing some light modifications both for appearance and performance so I figured I may as well start a build thread for the bike. But first I want to start with some maintenance items here's what I've found from my 10 mile ride home with the bike and the associated questions:

          Front tire - needs replacement due to the early stages of age cracks, thinking of going with the Dunlop D404
          Check brakes front and rear/new fluid
          Clutch - has an extremely hard pull to it. Is it common to put aftermarket springs in these bikes? Also which cover is for the adjuster?
          Oil change
          Front brake light switch doesn't work - has a non factory master cylinder so unsure of where to start on this
          Headlight side adjustment screw is missing
          Clean & lube chain
          Very extreme handle bar shake at certain speeds if I let go of it
          Mount tank - What is supposed to be there? See picture
          Fix original fuel petcock - The previous owner said it didn't work, and there's an inline aftermarket petcock, are the original ones still available?
          New plugs, check timing - possibly new points
          Lube all cables

          Anything I'm missing in the list that you think should be done? Once I complete the list I'm going to move on to replacing/repainting parts that have rust on them.
          Stay away from the Dunlop 404 in my opinion as they get real nasty towards the end of their life. The Shinko 230 Tourmaster is a much better tire with better life all the way through at about the same or less price

          They do make a hydraulic brake light switch that you can get from Z1 Enterprises. It uses a banjo bolt to screw into your MC and connects into your wiring. The biggest issue with them is that you have to pull on the brake lever a short distance before it activates the light so it's harder to just "flash" your brake lights at someone.

          I would look at replacing the bearings both in the steering stem and in the wheel. That with new tires will help you immensely

          What kind of condition is the chain in? You might want to replace it and when you do, you must replace the sprockets at the same time as they all wear together.

          For some parts, like the headlight adjustment screw, use your favorite Suzuki dealership but remember that most parts counter folks don't know or care about your aged bike. I recommend using the parts fiche to record the numbers and give them to the parts counter. They will still get most everything though it can take up to two weeks as they have to order from their warehouse. The forum's favorite dealership though is Parts Outlaw (www.partsoutlaw.com) in Florida as they have the best service and prices.

          Z1 also sells a very good petcock for the bike and their customer service is top notch. You'll get their parts in about 3 - 5 days.

          Please do a valve adjustment and clean the carbs from the beginning so you have a solid base to start with. If you start the process at the same time you order the parts you need (gaskets, O-rings from www.cycleorings.com, etc), everything can be finished about the same time.
          sigpic
          Cowboy Up or Quit. - Run Free Lou and Rest in Peace

          1981 GS550T - My First
          1981 GS550L - My Eldest Daughter's
          2007 GSF1250SA Bandit - My touring bike

          Sit tall in the saddle Hold your head up high
          Keep your eyes fixed where the trail meets the sky and live like you ain't afraid to die
          and don't be scared, just enjoy your ride - Chris Ledoux, "The Ride"

          Comment


            #6
            Good to know about the Dunlop as thats the rubber currently on my ride..

            Comment


              #7
              Well thanks for the suggestions so far. Tire is planned for tuesday, still haven't decided on it and open to suggestions but a shop near me has most of them in stock. The next thing I want to tackle is the clutch that way it'll at least be safe to test ride a little until everything gets done. So far I've lubed up the connection at the control lever and the mechanism at the engine side and it's still super hard to pull. Not sure if this is normal, but it seems as if the shaft to the clutch moves up slightly before it starts to rotate and I think this might be the problem but any advice is appreciated. Is there a bushing behind the mechanism? I'm going to order a new cable just because of the age but it seems to be moving smoothly. Anything else to check on this?
              The current garage:
              1978 GS750
              1975 GT750M
              1984 CB700SC
              1982 XJ650 Seca Turbo
              1975 RD250 - 350 conversion

              Comment


                #8
                It's possible someone put in heavy duty springs so you'll want to check them and replace at least half with OEM.
                sigpic
                Cowboy Up or Quit. - Run Free Lou and Rest in Peace

                1981 GS550T - My First
                1981 GS550L - My Eldest Daughter's
                2007 GSF1250SA Bandit - My touring bike

                Sit tall in the saddle Hold your head up high
                Keep your eyes fixed where the trail meets the sky and live like you ain't afraid to die
                and don't be scared, just enjoy your ride - Chris Ledoux, "The Ride"

                Comment


                  #9
                  Any chance there is a marking or something on the factory springs? I was thinking of using a borescope so I know for sure before I pull it apart
                  The current garage:
                  1978 GS750
                  1975 GT750M
                  1984 CB700SC
                  1982 XJ650 Seca Turbo
                  1975 RD250 - 350 conversion

                  Comment


                    #10
                    Here's an update for today. Parts are on the way and I got the new tire fitted, unfortunately I did end up with the Dunlop but the rear is about a year old and when it starts getting low I think I'm just going to replace them as a set and after doing some reading I think the Shinko 230 is what that set will be. I planned on repacking the wheel bearings but it looks like someone has put in sealed bearings and they spin just fine so I put it pack together as is. I think I figured the clutch out, the lever arm that the cable goes to was not on the flat properly and the cable was way out of adjustment. Seems to be a little better but still slightly stiff, I'll know for sure after some more riding.
                    Last edited by The1970's; 04-18-2017, 03:29 PM.
                    The current garage:
                    1978 GS750
                    1975 GT750M
                    1984 CB700SC
                    1982 XJ650 Seca Turbo
                    1975 RD250 - 350 conversion

                    Comment


                      #11
                      More problems

                      20170419_141417.jpg

                      Finally got a better picture or the bike. I rode it to work yesterday, a good 50 mile round trip and found some more problems. First obvious problem is that it'll probably need a clutch replacment relatively soon. Noticed a vibration under braking in the front so I may have a warped rotor and can't seem to find a replacement online anywhere. Also, in typical GS fashion the battery does not go anywhere above 12.5 Volts at any RPM. Strangely enough I've done about 70 miles on the bike so far using only the electric start and lights on the whole time and have never had a dead battery. I guess I'll just start going through the stator papers to find the problem.
                      The current garage:
                      1978 GS750
                      1975 GT750M
                      1984 CB700SC
                      1982 XJ650 Seca Turbo
                      1975 RD250 - 350 conversion

                      Comment


                        #12
                        Oh no, I didn't realize it was difficult to find another rotor, I'm in the same boat with my GS750 which I didn't even mention. When I was riding it last fall it had a definite wobble when braking, especially at low speeds.

                        I haven't gone through my charging system yet since I'm still waiting on parts to get it running correctly, but funny enough there is a parts dealer here in Sweden in Uppsala that sells new stators, it's nice to know if you have to go there.

                        Wow, your bike looks great cosmetically.

                        Comment


                          #13
                          Exhaust

                          Just a quick update: I've been through most of the list with the exception of the brakes so far. I also painted the exhaust because I just couldn't stand the look of the rusted header pipes. It came out alright, definitly better than it was. While I'm here does anyone know what aftermarket exhaust this is? It came on the bike when I got it. I also put in new plugs as the old ones where the wrong heat range and boy did they make a huge difference. Now that I've got it riding pretty well I think i'm going to start doing some modifying. First thing to go is going to be the mirrors, but I'll give another update when I get to that.
                          20170430_184108.jpg
                          The current garage:
                          1978 GS750
                          1975 GT750M
                          1984 CB700SC
                          1982 XJ650 Seca Turbo
                          1975 RD250 - 350 conversion

                          Comment


                            #14
                            Doesn't the 78 have points? I would upgrade to Dyna ignition either way. That includes coils. If the bike was made with points, get the 5 ohm coils, if not you can use 3 ohm coils. It's a coil life issue that's a bit argumentative, and the subject of a lot of back & forth on some forums. I have personally burned up 2 sets of green Dyna coils over the years by getting this backwards. Not looking to start anything, just google it for your own opinion.

                            Comment


                              #15
                              V&H? It's hard to tell from this angle.
                              GSRick
                              No God, no peace. Know God, know peace.

                              Eric Bang RIP 9/5/2018
                              Have some bikes ready for us when we meet up.

                              Comment

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