Announcement

Collapse
No announcement yet.

Still Missing.

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

    Still Missing.

    Synched the gs850 carbs. They have been dipped for 24 hours, the works. It is still slow to start from a cold start, and idles pretty low. Probably takes at least 5 minutes of warm up time to get it out on the rode. It stumbles and misses quite a bit within the first 10 minutes of riding (city riding). After I've ridden it for a while it evens out and is pretty good. Above 4000 rpms it is outstanding and has all the power I'd hoped it would have. Below 4000 rpms even after it is warm, it is not as impressive.

    Any ideas?

    Scudder

    #2
    Is the bike stock? Air filter clean and oiled? Airbox end caps sealed with good foam? Where are the pilot screws set?
    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


      #3
      Everything is stock, and sealed. The screws are at 2 turns out.

      Scudder

      Comment


        #4
        Originally posted by Scudder View Post
        Everything is stock, and sealed. The screws are at 2 turns out.

        Scudder
        Try 3 turns and see if that helps.

        Valves been adjusted lately?
        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
          My '82 850GL is slow to warm up as well, unlike my '81 1100E which just roars to life regardless of the weather.

          Like Ed says, try turning the mixture screws out a full turn & see if that helps. Proper valve clearances are a must!

          A few other random thoughts:
          - Are the carbs sync'ed ?
          - Have you checked the voltage at the coils?
          - If stock plug wires, replace the plug caps with new NGK ones.
          - Raise the idle (when warm) to around 1200-1500 RPM.
          - When you dipped/cleaned the carb bodies, are you certain you cleared the tiny passage thru that brass tube that sticks down into the float bowl?
          - Cleared the tiny passage in the float bowl where that brass tube sticks into?
          Mike
          '85 GS550L - SOLD
          '85 GS550E - SOLD
          '82 GS650GL - SOLD
          '81 GS750L - SOLD
          '82 GS850GL - trusty steed
          '80 GS1100L - son's project bike
          '82 GS1100G - SOLD
          '81 GS1100E - Big Red (daily rider)

          Comment


            #6
            Will increasing to 3 turns out richen or lean it out?

            I've not checked the voltage from the coils, but I've changed the caps, and adjusted the valves, and synched the carbs.

            I am so close to having it the way I want, this is the final thing. When I get on the throttle in 1st, 2nd or 3 third gear, it just doesn't have what it should.

            Scudder

            Comment


              #7
              Two turns open on the idle mixture screw is usually too little (as others have pointed out). Start with 2.5 to 3 turns.
              Originally posted by hikermikem View Post
              - When you dipped/cleaned the carb bodies, are you certain you cleared the tiny passage thru that brass tube that sticks down into the float bowl?
              - Cleared the tiny passage in the float bowl where that brass tube sticks into?
              Mike
              That was my first thought. To clarify, I believe Mike is suggesting you check the passage in the float bowl that allows fuel into the small diameter hole the brass tube goes into. It will be in the bottom of the main body of the float bowl and leads into the tube hole.

              But I would practically bet money on one or more clogged pilot jets. Remember, pin drills are your friends (properly used, of course!).

              It will be one of the smallest drills, #'s 78 through 80.

              Comment


                #8
                Alright. 3 turns it is. I'll go back into the carbs and make sure all the small holes are clear this weekend. When I cleaned them, all the holes were clear (I thought). I used a tool off of Z1 and poked it into all the tiny holes. I'll know for sure after the weekend. I'm goin' try the three turns out first. If that is the problem then that is an easy fix.

                So... will 3 turns out, richen things or lean things out. My airbox is sealed, I have a new filter and it is lightly oiled.

                scudder

                Comment


                  #9
                  Further open allows more fuel though. That circuit is for just off idle though, not when running at speed. Clogged pilot jets are the most likely reason for poor low speed running performance.

                  Maybe the bike isn't running on all cylinders. When you first start the bike, carefully touch each exhaust header, or spray them with water, to see if all four are firing.
                  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


                    #10
                    All cylinders are firing, so that narrows it down to the pilot jets. Thanks.

                    Scudder

                    Comment


                      #11
                      Scudder, in my experience, it is very common to rebuild carbs, know that all pilot jets are clear, and then it runs like crap again in short order. These jets are tiny tiny tiny and the slightest spec of crud will close them up again. If you suspect any dirt or rust at all in your fuel, replace your fuel line and install a decent fuel filter in the line. There have been bikes when I've had to clear those jets four times before getting the bike to run right!

                      Also, the reason I recommend using pin drills to clear the pilot jets is that simply poking a wire through the holes of the pilot jets only ensures that the hole goes all the way through. It does not ensure that the hole is the right size. Even after poking a wire through the hole, there may still be shellac buildup inside the pilot jet, making it smaller than it should be. Look at that pin dril kit I recommended. Put the shank (smooth) end in the hole to gauge size. Then use the fluted (drill) end to clear the hole. You do this by hand, not with a power tool. It's very easy to do. I hold the pin drill still in the pin vise and twirl the jet onto the drill.

                      I also find that pilot jets are undersized a little for environmental rules. Opening them up to the next drill size usually helps (in my opinion). And if you mess it up, the jets are really cheap anyway if you want to go back down a size.
                      Last edited by Guest; 04-11-2012, 04:04 PM.

                      Comment


                        #12
                        Thanks. I ordered a set of the pin drills. Cheap and a good investment. I appreciate the advice. I'd hoped to get the carbs clean the second time, but it looks like it'll take another attempt.

                        Scudder

                        Comment


                          #13
                          Headed back into the carbs this morning. Used the very small pin drill bits to clean out the pilot jets. Discovered that an opening in carb #1 bowl was totally clogged. Couldn't get it clear. Luckily I had another bowl with the opening clear. Reassembled everything, and.... problem solved. Runs great at all rpms. The choke issue I've had has been solved too. Revs to about 3500 on full choke, and quickly can be reduced and return to idle. Thanks a million to all who helped. I appreciate it.

                          Scudder

                          Comment

                          Working...
                          X