81' rRunning a little rough and backfiring

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • jacksonjeffrey1
    • Feb 2026

    #1

    81' rRunning a little rough and backfiring

    My 81 GS850GLX is running a little rough until I get up to speed and backfires when I decelerate. I have replaced the plugs and am gearing up to do the carbs, intake boots, etc., but was wondering if there is something I should check/adjust now until I actually start the work.
  • tom203
    Forum Guru
    Past Site Supporter
    • Aug 2010
    • 8925
    • Norway,Maine

    #2
    Clean your carbs properly- it's likely your idle/slow speed circuits are gummed up. Good idea to test petcock to eliminate it as problem; when mine leaked down vacuum hose to #2 carb, I got backfiring in left exhaust at low speed.
    1981 gs650L

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

    Comment

    • jacksonjeffrey1

      #3
      When you say "test the petcock to eliminate it as a problem:, what do you mean exactly? Are you suggesting I check for fuel leaks? Air leaks? What?

      Comment

      • habsdoc
        Forum Mentor
        • Feb 2012
        • 333
        • Winnipeg Manitoba Canada

        #4
        Petcock

        You check to see if you are getting any fuel flowing down the vacuum line. If there is any fuel, you will need a new petcock.
        1981 GS 1000GLX.
        1981 GS 1000G.
        1981 GS 650GLX.
        1975 TS 185.
        1972 100. Kawasaki.
        1968 100. Suzuki.
        1970 Z 50. Honda.
        1984 CT 70. Honda. (Kids)
        1982 DS 50. Suzuki. (Kids)

        Comment

        • tkent02
          Forum LongTimer
          Past Site Supporter
          • Jan 2006
          • 35571
          • Near South Park

          #5
          While you are waiting, adjust the valves. Probably nothing to do with the issue you are having now, but it needs to be done. Actually it could possibly be part of the issue you are having. Either way it needs to be done.
          http://img.photobucket.com/albums/v5...tatesMap-1.jpg

          Life is too short to ride an L.

          Comment

          • Triam

            #6
            Originally posted by tkent02
            While you are waiting, adjust the valves. Probably nothing to do with the issue you are having now, but it needs to be done. Actually it could possibly be part of the issue you are having. Either way it needs to be done.
            I love how that's everyone's default advice on this site. Valves are nearly worshiped. I told my friend that got me into riding that he should adjust his valves (He's had the bike for 5 years now and still hasn't even checked the clearances) and he thinks I'm blowing smoke.
            Doing a complete valve job on his pitted valves will be fun.

            Comment

            • Guest

              #7
              Originally posted by Triam
              I love how that's everyone's default advice on this site. Valves are nearly worshiped. I told my friend that got me into riding that he should adjust his valves (He's had the bike for 5 years now and still hasn't even checked the clearances) and he thinks I'm blowing smoke.
              Doing a complete valve job on his pitted valves will be fun.
              If you have been hanging around for a while , then you already know that there is a whole list of default advise . It is called the top ten Noob mistakes. Also your welcome package from. Bascliff is a great way to navigate your way through the list. Read it, live it and you and your bike will love it.

              Comment

              Working...