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Help! Hard to rev past 6000rpm / No power

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    Help! Hard to rev past 6000rpm / No power

    I tried the search but got nothing.

    Ok I got the solenoid figured out, I didn't realize there was a clutch switch and even in neutral I had to hold the clutch in. She starts right up at the push of a button and will stay running. When I'm riding it it doesn't want to pull past 5-6k rpm it just kinda goes up to that and stop. If I change into second it just kinda looses power at 20 mph. Any suggestions?

    1981 GS250T 1008 original miles. So far it has a new battery, a new chain, I cleaned carbs, a new clutch cable, I adjusted clutch and I changed the oil.

    Thanks,
    Primo

    Also anyone one know what the spark plugs are supposed to be gapped at?

    #2
    Plugs are usually gapped around .028"

    Lack of power at higher engine speeds sounds like it's not getting enough fuel. This raises a question ... just how did you 'clean the carbs'? If you opened up the float bowl and just wiped out the crud, you need to go back and clean them. The best suggestion I can give is to order new o-rings for the carbs from www.cycleorings.com, then get a can of Berryman's carb dip and clean them properly. There is a section in the Garage on How to Clean CV Carbs that works very well. The only thing I would suggest different is the time that the carbs spend in the dip. The directions say "15-30 minutes", I say "15-30 hours." That's right, leave each one in overnight. Keep all the parts for each carb together, don't mix them up.

    While the carbs are in the dip, and you have nothing else to do, check the valve adjustment. Clearance is so tight on these bikes, you don't want to burn up the valves because you thought an adjustment was too hard.

    Install all the new o-rings, do a bench sync, install the carbs. When the bike is warm, do a dynamic sync on the carbs. Now you should be good to go.


    .
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    mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
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    #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
    #2 son: 1980 GS1000G
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    Comment


      #3
      I followed the How to clean carbs tutorial to clean my carbs and left the bodies in cleaner overnight. The only thing I wans't able to clean were the imulsion tubes. I tried the wooden dowl and hammer technique but just couldnt get them out. Could they be the source of my troubles?

      Primo

      Comment


        #4
        Originally posted by Primo View Post
        I followed the How to clean carbs tutorial to clean my carbs and left the bodies in cleaner overnight. The only thing I wans't able to clean were the imulsion tubes. I tried the wooden dowl and hammer technique but just couldnt get them out. Could they be the source of my troubles?

        Primo
        My guess is that if the holes on the sides of the emulsion tubes are plugged it would effect high rpm running. Another thing that could cause the problem is a bad ignitor. You might want to try cleaning all the electrical connectors to make sure everything has proper contact.

        Good luck.
        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


          #5
          I would check the mechanical advance behind the signal generator. Take it off and make sure it turns freely. Take it all apart and clean the whole thing and lube any of the rotating joints. Keep an eye on all the clips and washers when you are taking it apart.

          Comment


            #6
            Originally posted by Kaptain Ketchup View Post
            I would check the mechanical advance behind the signal generator. Take it off and make sure it turns freely. Take it all apart and clean the whole thing and lube any of the rotating joints. Keep an eye on all the clips and washers when you are taking it apart.

            Does anyone have a picture of the mechanical advance? I have no idea what that is.

            Primo

            Comment


              #7
              Stolen from ebay:





              It's behind the pickup plate. Mark the position or have a timing light on hand to reinstall it.

              Comment


                #8
                Could a wrong float level make the bike do this? Where is the float supposed to be set on this bike? I'm going to pull it back apart and see if I can get the emulsion tubes out and wanna do it right when I put it back together.

                Primo

                Comment


                  #9
                  The intake boots between the carbs, and airbox are not sealing properly.

                  Comment


                    #10
                    I replaced the o-rings in the intake boot with a couple of viton ones, it seems to have gotten alittle better but still not great. I got her up to 40 but that was going downhill. I did notice that the boots from the air box are pretty loose, I'll get some new clamps and try cinching that down tommorrow. On a side note what should the valve clearances be?

                    Primo
                    Last edited by Guest; 10-02-2007, 08:33 PM.

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