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1985 GS450 starting issues

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    1985 GS450 starting issues

    Hi, I have owned this bike for 2 months now and have yet to ride it.

    It barely started right after purchase but was only hitting on 1 cylinder ... so I pulled the carbs and cleaned them real good and reinstalled. Attempted a start and all lights were on but the starter motor turned over very slowly with NO start, so I pulled the battery out and charged. The battery read 13.2 after charge but the next morning it went down to 12.6. Lights turned on but slow starter and no start. Then I removed the battery ground to the rear of the engine, cleaned and replaced. Now I get NO lights and NO starter movement at all, with ignition on. It's getting worse every time I try to get a start! Either I blew some main fuse or the battery is total crap!

    Can I use a car battery and jumper cables to the starter solenoid and engine ground ... to test starter motor without hurting the system?

    I checked the inline fuse on the left side and it seemed fine. Is there any other fuses elsewhere to find and check? The top of the neg battery terminal seemed to be touching the battery box, so I laid tape to stop contact there. Behind the battery box is an electrical part I have not identified as yet and a female double connector NOT connected to anything. The wire color looks like black with white stripe. Can someone tell me what that double female black and white connector goes to?

    I have ordered a new battery .... as the old one looks a little sulpherized. It charges up fine but loses voltage fast. I was hoping all my work to fix the bike and battery would yield a good start and strong running of the engine today .... not to be. I'm also worried that the starter motor might need a rebuild .... would I have to remove the carbs to get that out? Ouch.
    Dennco2
    1985 GS450
    Stock condition and a work in progress

    sigpic

    #2
    Can I use a car battery and jumper cables to the starter solenoid and engine ground ... to test starter motor without hurting the system?
    Only do this with the car engine off.

    If you have a voltmeter, measure the voltage right at the battery terminals using the procedure in Quick test in my signature. If you post all of the results, we can probably get a pretty good idea of what is wrong or at least figure out a next step.

    B/W is harness ground ; if you got a factor schematic you could see that. Check Basscliff's website; he has many manuals uploaded.

    Comment


      #3
      Sounds like you have a few things going on.
      Once you get the starter cranking...
      Have you done valve clearances yet? When I got my GS450 I waited on this and it's really pretty simple, lots of help over on BassCliff's site.

      The Help your bike won't start! thread might be of some interest to you.

      I'm sure somebody is also going to ask you how you cleaned your carbs and if you replaced the O-rings.
      1980/1981 GS450 - GS500 Cylinder + Piston Swap - "De-L'ed", custom seat, CB350 bits, 18" rear, etc.
      1977 GS550
      1977 GS750 - Cross country trip thread

      Comment


        #4
        Originally posted by sam000lee View Post
        Sounds like you have a few things going on.
        Once you get the starter cranking...
        Have you done valve clearances yet? When I got my GS450 I waited on this and it's really pretty simple, lots of help over on BassCliff's site.

        The Help your bike won't start! thread might be of some interest to you.

        I'm sure somebody is also going to ask you how you cleaned your carbs and if you replaced the O-rings.
        As far as the cleaning of the carbs .... I followed the GS tutorial on this forum as best as possible. Dipped carb bodies and parts, used air pressure to blow dry the jets and passageways.

        I just read the Bike Wont Start thread. Lots to digest there. I will be checking valves altho at this point it seems like a daunting task. I have a GS450 manual with supplements.

        For now, I just wanted a small victory to get it started and hear the engine run a bit. Yesterday I charged the battery again to 13 volts showing and when I turned on the ignition switch not even the dash lights lit up! (new battery is coming on Tuesday) Past efforts to start showed bright dash lights but very slow starter motor turnover .... like either the battery or starter motor or grounds or ALL of them were in poor shape. So far I have cleaned the battery ground to the engine. Currently I have clean carbs with fresh O-rings including the 40mm, brand new petcock, new fuel and vac rubber hoses, clean tank inside, fresh fuel. I am trying to eliminate the culprits one by one.

        Yesterday, I had both my centerstand and kickstand in the down position. Does that prevent a start up with clutch handle pulled? Does the clutch handle have to be pulled ALL the way back to make the starter connection? I don't have an owners manual ... but see that I can download that from the manuals section. The PO said this bike ran fine for his 5 years of ownership ... except for this year so he sold it. He didn't believe in maintenance ... but only rode it about 500 miles total (he said).
        Dennco2
        1985 GS450
        Stock condition and a work in progress

        sigpic

        Comment


          #5
          Try jumping the starter motor solenoid. Make sure bike is in neutral - on centerstand too as backup. Key off . Use a small jumper wire to connect battery positive to the small terminal on solenoid (this is the terminal the starter button operates): solenoid should "click" and starter should spin. This bypasses any safety switches . Note that solenoid frame has to be grounded for even this to work.
          Last edited by tom203; 10-07-2016, 04:15 PM.
          1981 gs650L

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

          Comment


            #6
            Is this one of the models that the clutch lever has to be pulled in to start? (some of mine pre date this safety feature, some don't). Have you cleaned the contacts for the clutch lever switch yet? Same switch as the front brake light on mine.
            Last edited by smilinbrad; 10-07-2016, 09:06 PM.

            Comment


              #7
              Yes, I found out by surprise that I have to pull the clutch lever to engage the starter motor. I have not cleaned the contacts for the clutch lever .... where is it? I'll clean it asap ... as soon as I can find it.

              I am sure my current battery is junk and can hardly wait till my new battery arrives. My OTHER bike sat for a month and the 5 month old battery discharged and went bad on me. I charged it and it showed 13.2 volts but wouldn't even begin to turn over the starter. Plopped a new one in .... and all was well again.
              Dennco2
              1985 GS450
              Stock condition and a work in progress

              sigpic

              Comment


                #8
                A little update on this starting problem.

                I bought a new YB battery and acid and charged it to full. While removing the old battery from the bike ... I noticed the positive battery terminal connector had cracked in half .... so no wonder no power getting to the bike. I crimped and soldered another copper connector on the positive side wire harness and installed new battery .... and got power to every where but STILL not to the starter. It didn't even click the starter relay.

                Also I noticed the kickstand light will not go out, even when in the up position. Would that effect the starter situation? Anyway, I am slowly reducing the list of likely causes for starting issues down to the starter solenoid, the positive wire to the starter motor, or the starter itself. Of course the starter switch could be bad too. Can someone direct me to a previous discussion on how to diagnose where the problem is ... or throw out some more suggestions on how to go about tracking down the problem? My knowledge of wiring issues is still quite limited even though I am working on it.
                Dennco2
                1985 GS450
                Stock condition and a work in progress

                sigpic

                Comment


                  #9
                  ". and got power to every where but STILL not to the starter. It didn't even click the starter relay."

                  Reread my previous post on jumping the solenoid- note the stuff about solenoid case being grounded for even this to work!

                  1981 gs650L

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

                  Comment


                    #10
                    Okay, I jumped the solenoid using a spare battery and jumper cables and it clicked and the starter motor spun up. So I flipped on the ignition switch and finally was able to start the engine. As before, it was only firing on the left cylinder and would only idle or rev slightly above it. Stone cold right side pipe.

                    I should have also tried to start it again by pressing the starter button, but didn't. When I 1st got the bike I could use the button but the starter motor turned over so slowly the engine most of the time would NOT start. Weeks later, not even a click by using the button, even recently after installing a new charged battery. Am I right in suspecting a bad starter switch which needs cleaning?

                    Previously, I had pulled the plugs and confirmed I was getting spark to both. Then I super cleaned both carbs in and out and remounted ... making the assumption fuel wasn't getting to the right cylinder. Today, after firing the engine up to idle I still have the same problem ... NO firing on the right cylinder. I have an OLD compression tester which just pushes down over the SP hole, instead of threading into it. I need to accurately check compression, so will be looking to buy a good one. Any other suggestions?
                    Dennco2
                    1985 GS450
                    Stock condition and a work in progress

                    sigpic

                    Comment


                      #11
                      You still need to clean up your electrical connections,, but progress is good.
                      As to carbs.... Your "super cleaning" is likely inadequate, but go ahead and explain. These carbs have tiny passages in pilot circuit and once gunked up they resist quickee cleaning methods. You need the pilot circuit clean to get the right carb to get enough fuel or it won't come alive. Have a look here (your 1985 carbs should be similar)

                      http://members.dslextreme.com/users/...ning_guide.pdf
                      Last edited by tom203; 10-22-2016, 07:49 AM.
                      1981 gs650L

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

                      Comment


                        #12
                        Originally posted by tom203 View Post
                        These carbs have tiny passages in pilot circuit and once gunked up they resist quickee cleaning methods.
                        That font joke was funny good sir.

                        Checking the valve clearance and compression will be the best thing. Most people who buy bikes like ours don't check and if the clearance is already off, things will keep getting worse.

                        Comment


                          #13
                          Although I've never seen it, I'm sure there is a starter relay in there somewhere. If your battery is charged, the starter button contact clean and everything is grounded as it should be and you can power the starter motor directly and it spins, maybe the relay is toast. They aren't expensive and are easy to install.
                          I think you carb is still plugged up or way out of sync though.

                          Comment


                            #14
                            Today I went out to jump my starter with a compression tester threaded in the hole. I got 115 lbs psi and it seemed to be holding that pressure for a long time after. Is 115 within compression limits and enough to fire atomized gas? I did NOT compare the left cylinder, but could if it is useful.
                            Dennco2
                            1985 GS450
                            Stock condition and a work in progress

                            sigpic

                            Comment


                              #15
                              "Is 115 within compression limits and enough to fire atomized gas?"

                              plenty, BUT there has to be enough atomized gas in there.. You didn't explain your carb cleaning technique
                              1981 gs650L

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

                              Comment

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