Announcement

Collapse
No announcement yet.

GS850 gasp when accelerate

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

    GS850 gasp when accelerate

    Hello all,

    I bought a GS850 1981couples months ago, and the bike is in pretty good conditions, just 5K miles used since new, but I has a problem, the engine start easy and idles well but when I accelerate it, it doesn't go above 3 to 4K rpm. As it is being stopped or years, I decided to clean the carburetors, them I noticed that it was without the air filter foam.
    I bought the filter, gaskets, orings and disassembled the carburetors. As expected due to the low mileage, everything was new, probably the first time it was serviced. I noticed that the pods were dry and cracked, so I bought new ones.
    After all was cleaned I re-assembled the carbs and filter in the bike, started it, and the problem remain the same...
    One thing that I`m in doubt is the filter assembly in the air box, the filter metallic body (that holds the foam), does not have a gasket on the sealing face to the air box, and I think it should, because there is a gap (round 1/8") between this filter metallic body and the air box, and that can influence the vacuum and the air/fuel ratio. I tried to find a picture of this filter to check if it has a gasket there, but didn't found.
    I would like to know if my hypothesis (missing gasket causing the issue) makes sense, or if there is something else that could be the cause.

    Thanks for your help

    #2
    Air gaps can cause that problem
    How are the gaskets on the air box end caps?
    Did you follow the tutorial when you cleaned your carbs?
    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


      #3
      Hello. Yes, I fully read the tutorial for the carbs cleaning.
      It does not have gaskets either between the metallic body that supports the foam and the air box (só there air that pass through the gap, bypassing the foam of the filter) and also does not have gaskets on the air box caps.
      As I didn’t found the gaskets to buy I’m planning to do them using rubber. Do you have any suggestions on this? I didn’t found any picture of this filter assembly, do you have any?
      thank you very much for you support!

      Comment


        #4
        Originally posted by Paulo Perez View Post
        Hello. Yes, I fully read the tutorial for the carbs cleaning.
        It does not have gaskets either between the metallic body that supports the foam and the air box (só there air that pass through the gap, bypassing the foam of the filter) and also does not have gaskets on the air box caps.
        As I didn’t found the gaskets to buy I’m planning to do them using rubber. Do you have any suggestions on this? I didn’t found any picture of this filter assembly, do you have any?
        thank you very much for you support!
        Here's a complete air box from an 81 850G. You can at least see what the black rubber seals look like that go under the chrome ends and the filter basket with a foam filter on it. Peel and stick weather strip from the hardware store works instead of the rubber seal on the ends. I also used some of that weather strip around the top of the filter basket.

        Here's a good drawing and a resource for parts. https://www.partsoutlaw.com/oemparts...ce/air-cleaner

        Last edited by Burque73; 12-10-2018, 12:34 AM.
        Roger

        Current rides
        1983 GS 850G
        2003 FJR 1300A
        Gone but not forgotten 1985 Rebel 250, 1991 XT225, 2004 KLR650, 1981 GS850G, 1982 GS1100GL, 2002 DL1000, 2005 KLR650, 2003 KLX400

        Comment


          #5
          Originally posted by Paulo Perez View Post
          Hello. Yes, I fully read the tutorial for the carbs cleaning.
          It does not have gaskets either between the metallic body that supports the foam and the air box (só there air that pass through the gap, bypassing the foam of the filter) and also does not have gaskets on the air box caps.
          As I didn’t found the gaskets to buy I’m planning to do them using rubber. Do you have any suggestions on this? I didn’t found any picture of this filter assembly, do you have any?
          thank you very much for you support!
          Hi Paulo

          Yes, that gap between the filter and the airbox should be sealed. Stick foam "weatherstrip" onto the airbox, and when the filter is mounted it will seal up against that foam strip.

          Here is a guide on how to seal your airbox. http://members.dslextreme.com/users/cbsaunders/gs/airbox-sealing.pdf

          Good luck!
          1981 GS850G "Blue Magic" (Bike Of The Month April 2009)

          1981 GS1000G "Leo" (Bike Of The Month August 2023)

          Comment


            #6
            Thank you for your help!

            Comment


              #7
              Let us know how it works
              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


                #8
                Sure, I`ll work on it on Saturday and post the results here. Thanks!

                Comment


                  #9
                  Worked very well, I sealed the air box gaps, cleaned and oiled the air filter, reassembled on the bike and it is running perfectly now.

                  Thanks for the help!!
                  Attached Files

                  Comment

                  Working...
                  X