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    GS750E hard starting

    First of all, I'm new to this whole forum thing. So please be patient if possible. So my issue is this, I bought this 82 750 for $400 on Craigslist. In it he said it was cold blooded. I figure I can handle that right? Well, being new to bikes it was a little more complicated than I thought. With a whole heck of a lot of starting fluid and some extra juice it'll start after 10-15 minutes of cranking. I pulled apart all the carbs, cleaned them thoroughly and put them back on. No difference. I just pulled apart the valve cover and discovered nearly all the valve shim clearances were too small for my .04mm feeler gauge to get into. I've been reading how important that is so I'm sure it hasn't been done in quite some time. It also has a bit of a "dead spot" about half way up the range. I've searched and can't find exactly what I want to know. My question is what other General maintenance should have been done that the previous owner may have forgotten such as the Valve shims? I apologize for the long-windedness! Any help is very appreciated
    -Robin

    #2
    If the valve clearances have closed up it will run poorly and be difficult to start (and if they have been like that for a period of time then it may have burnt valves). So, get them into spec first.

    A new set of spark plugs will probably help a lot as well.
    Current:
    Z1300A5 Locomotive (swapped my Intruder for it), GS450 Cafe Project (might never finish it....), XT500 Commuter (I know - it's a Yamaha )

    Past:
    VL1500 Intruder (swapped for Z1300), ZX9R Streetfighter (lets face it - too fast....), 1984 GSX750EF, 1984 GSX1100EF (AKA GS1150)
    And a bunch of other crap Yamahas....

    Comment


      #3
      I have new shims on their way. I should also mention it makes no difference whether the choke is on or off(yes the choke is fully engaging, no slop in the cable). It also has air pods instead of an air box and 4-1 exhaust. Don't know if this makes a difference with the hard starting but throwing that in there as well. Thank you for the help.

      Comment


        #4
        "It also has a bit of a "dead spot" about half way up the range. I've searched and can't find exactly what I want to know"

        the carbs were not likely rejetted for the pods/ exhaust setup. You'll need to pull them again and find out . Get valve clearances correct.
        the "choke" system feeds extra fuel up a little tube in side of each fuel bowl- make sure this is not gunked up. Just how "thoroughly" did you clean these carbs?

        did you see this regarding common issues?

        1981 gs650L

        "We are all born ignorant, but you have to work hard to stay stupid" Ben Franklin

        Comment


          #5
          The '82 750 shouldn't have any shims. The last GS 750 with shims was in 1979. Show us a picture of the engine?


          Life is too short to ride an L.

          Comment


            #6
            Sorry, this is the only image I have. I might be wrong on the year but that's what I had been told. But it would make sense considering the front brakes are round pads.
            Attached Files

            Comment


              #7
              That is definitely from a 1979 or older. What's the VIN and what's the engine number? Could be a bike that sat at a dealer until 1982, could be someone swapped engine and brakes for some reason, could be a completely fraudulent bike.

              But yeah, getting the valve clearances right is the most important thing, as having then too tight like yours will cause the valves to burn.
              Last edited by tkent02; 01-20-2016, 12:24 PM.


              Life is too short to ride an L.

              Comment


                #8
                Where would a guy find the VIN? (Can't find title)

                Comment


                  #9
                  Should be on the neck of the frame, just below the handlebars on the left side as you sit on the bike.
                  Larry

                  '79 GS 1000E
                  '93 Honda ST 1100 SOLD-- now residing in Arizona.
                  '18 Triumph Tiger 800 (gone too soon)
                  '19 Triumph Tiger 800 Christmas 2018 to me from me.
                  '01 BMW R1100RL project purchased from a friend, now for sale.

                  Comment


                    #10
                    How can you buy shims if you don't know which sizes you need? You should first take each shim out, measure it and put it back - move to the next. BTW there's a shim exchange club on this forum.
                    -Mal

                    "The only reason for time is so that everything doesn't happen at once." - B. Banzai
                    ___________

                    78 GS750E

                    Comment


                      #11
                      Well I made the mistake of just assuming they could only go down to .00 but I got to thinking, maybe it could be in the negative? So I'm going to take the thinnest shim and put it in place of the others so maybe I can get a measurement? Let me know if my thinking is flawed. Learning as I go. The plus is I only ordered 2 shims.
                      The VIN is GS750E-32408

                      Comment


                        #12
                        Originally posted by Robinhood View Post
                        Well I made the mistake of just assuming they could only go down to .00 but I got to thinking, maybe it could be in the negative? So I'm going to take the thinnest shim and put it in place of the others so maybe I can get a measurement? Let me know if my thinking is flawed. Learning as I go. The plus is I only ordered 2 shims.
                        The VIN is GS750E-32408
                        Shim sizes range from 3mm down to the low 2's. As you cannot read a gap at the moment, buy one shim on the low end put it in each bucket and get a reading. You have to find out where you are before you can fix this. Email Steve to get an .xls spreadsheet to aid the math. You have to do this correctly!!!!!

                        Edit: Search for Steve (yes, that is his username) in the members list.
                        Last edited by allojohn; 01-21-2016, 10:39 PM.
                        -Mal

                        "The only reason for time is so that everything doesn't happen at once." - B. Banzai
                        ___________

                        78 GS750E

                        Comment


                          #13
                          Your bike is not an '82. It's a '79 or earlier.

                          Please check the newbie mistakes thread linked in my signature if you want to know some of the common problems to look out for.
                          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


                            #14
                            Also, stop using the starting fluid.

                            If you search the forum you will see many unfortunate accounts of those using starting fluid with serious engine damage. (If I remember right it washes the oil off pistons and they seize)

                            Comment


                              #15
                              Hi Robin, first of, ditch the starting fluid, do the mentainance on the valves/shims,sounds like you have the carbs sorted, the flat spot could be simply due to, to much oil in your air filter iv to keep mine almost dry with only a trace, try your bike with the filter dry and for the Hard Starting could well be bad connections and low voltage to the coils. Check for partially burned connections below the tank, if necessary replace, do the solder crimp and double shrink seal, check the voltage at the coils and if it's low take apart the kill switch and the ignition switch to check connections. If you have found the voltage to be low I'd strongly recommend you do the coil relay mod. It's all simple stuff and in great detail on the forum. Hope this helps, Stephen.

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