Announcement

Collapse
No announcement yet.

Trouble w/ my '77 gs 750

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Trouble w/ my '77 gs 750

    Rode My bike out to the desert a month ago and stupidly didn't check the oil levels. I just barely made it to my friend's house when the bike died and wouldn't move...it still started up but the clutch wouldn't engage...

    since then I have: Replaced the clutch, rebuilt the carbs, replaced air,oil and gas filters, battery is on trickle charge...

    The bike still doesn't perform properly. It takes a lot to get it started and when i try to come out of 1st gear and accelerate I lose RPMs, speed and then the bike stalls...


    any advice or help would be hugely appreciated...

    thanks in advance..

    j

    #2
    O.K. You say that you rebuilt the carbs. May I ask what procedure you followed? What did you replace? Do you have access to a multimeter? Answering these simple questions will help us answering your questions.

    Comment


      #3
      It's very difficult to diagnose what could be wrong until all the maintenance is up to date. For example: points clean and set properly, petcock clean and working properly, carbs clean, valves adjusted, airbox sealed, charging system checked, etc.

      I suggest you get out your service manual, look up the maintenance list, and get busy. After all the maintenance is done, then start troubleshooting.
      Ed

      To measure is to know.

      Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

      Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

      Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

      KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

      Comment


        #4
        yeah...we checked the points yesterday and looks like they may need to be replaced...also going to replace the plugs.

        We took off the carbs cleaned them thoroughly, replaced all the jets, gaskets and o rings....wondering if maybe i should go back in and put the old jets on...


        the charging system seems to be fine...

        A friend of mine said it sounded like possibly the bike wasn't firing on all four cylinders...


        j

        Comment


          #5
          In your first sentence, you mentioned not checking the oil???? Does that mean you rode it with no or little oil??????????? if so, the engine bearings and rings etc may be gone.. what was the oil level when it died??

          Comment


            #6
            Possible lack of compression

            Pr just new points and condensors
            1978 GS 1000 (since new)
            1979 GS 1000 (The Fridge, superbike replica project)
            1978 GS 1000 (parts)
            1981 GS 850 (anyone want a project?)
            1981 GPZ 550 (backroad screamer)
            1970 450 Mk IIID (THUMP!)
            2007 DRz 400S
            1999 ATK 490ES
            1994 DR 350SES

            Comment


              #7
              Yeah it was pretty much bone dry when I checked the levels...dumbed out big time...the bike is running now after I put the old jets back in...but the bike seems to be tripping as I accelerate and is lacking in power as I give it gas...bike seems to have no top end...

              any other ideas...recheck the jets again?


              thanks everyone...

              j

              Comment


                #8
                Originally posted by jayzer81 View Post
                Yeah it was pretty much bone dry when I checked the levels...dumbed out big time...the bike is running now after I put the old jets back in...but the bike seems to be tripping as I accelerate and is lacking in power as I give it gas...bike seems to have no top end...

                any other ideas...recheck the jets again?


                thanks everyone...

                j

                Get yourself a couple cans of ether and rig up spray nozzles so you can spray the GO juice right into the carb throats while riding. If that biotch acts up again, kick it in the teeth with a double shot!
                Last edited by Nessism; 12-29-2011, 02:00 AM.
                Ed

                To measure is to know.

                Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

                Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

                Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

                KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

                Comment


                  #9
                  Hi,

                  Have you adjusted the valves and checked the compression?


                  Thank you for your indulgence,

                  BassCliff

                  Comment


                    #10
                    Did you take a look at the oil filter to see if you are making any metal, anything on the magnetic drain plug. I you have any pieces in the filter that you can read part numbers on that's bad.

                    Comment


                      #11
                      Do a compression check First.
                      Otherwise you're just "guessing"....which will get you nowhere.
                      (based on the fact that no oil came out of the engine)

                      Borrow a compression tester or rent one from Autozone or similar autoparts store.
                      Because if you ain't got enough compression, it's never going to run right.

                      If you take a flashlight and peak threw the spark plug hole, you might be able to see if the cylinder walls are scoared badly, etc.

                      Comment


                        #12
                        We did a dry compression test...put new plugs on...a buddy took a look and thinks maybe the lobes on the camshaft might have gotten worn down...in which case anyone have any advice on that? Can I just replace the cam shaft?

                        trying to save my bike from certain death here...


                        thanks again...


                        j

                        Comment


                          #13
                          Originally posted by jayzer81 View Post
                          We did a dry compression test...put new plugs on...a buddy took a look and thinks maybe the lobes on the camshaft might have gotten worn down...in which case anyone have any advice on that? Can I just replace the cam shaft?

                          trying to save my bike from certain death here...


                          thanks again...


                          j
                          To prevent certain death, give it to someone else.
                          http://img.photobucket.com/albums/v5...tatesMap-1.jpg

                          Life is too short to ride an L.

                          Comment


                            #14
                            I'm pretty sure you ruined the engine by running it without oil. What were the results of the compression test?

                            Comment

                            Working...
                            X