1980 GS850 GL petcock

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  • David-Z
    • Feb 2026

    #1

    1980 GS850 GL petcock

    I went to my local shop looking for a replacement as the lever has been broken off of mine since purchase last fall. The guy pulled a bin of about 50-60 petcocks and not one matched the bolt pattern. He used a screw driver and said it was "functioning" properly, but even a rebuild kit wont come with the lever that I need. Has anyone has a similar problem? I scoped out a few of the bikes in the part/for sale section (and grant it my zoom isn't the best, nor the picture I was trying to zoom in on), but it looked like this missing lever is a common problem. Ebay had brand new for $99.xx, not sure if i want to drop that kinda coin on this. Any suggestions?
  • Dogma
    Forum Guru
    • Sep 2007
    • 7143
    • Mason, OH (SW)

    #2
    That bike's petcock never had a lever. It's was meant to be used with a screwdriver. It has only two positions: prime and run. There is no reserve. You have a range of about 100 miles before you should really be looking for gas (assuming the carbs are stock and working working right).

    If you decide to replace it, be aware that the mounting hole spacing is also unusual. I wouldn't advise bothering unless there are operational problems, such as behaving like it's out of gas at highway speeds.
    Dogma
    --
    O LORD, be gracious to me; heal me, for I have sinned against you! - David

    Skeptical scrutiny is the means, in both science and religion, by which deep insights can be winnowed from deep nonsense. - Carl Sagan

    --
    '80 GS850 GLT
    '80 GS1000 GT
    '01 ZRX1200R

    How to get a "What's New" feed without the Vortex, and without permanently quitting the Vortex

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    • tom203
      Forum Guru
      Past Site Supporter
      • Aug 2010
      • 8925
      • Norway,Maine

      #3
      The dreaded leverless petcock; check your mounting bolt centerline spacing if 50mm, then this guy has them for $50

      1981 gs650L

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

      Comment

      • David-Z

        #4
        Originally posted by Dogma
        That bike's petcock never had a lever. It's was meant to be used with a screwdriver. It has only two positions: prime and run. There is no reserve.
        I figured I learnbmore about petcock once I had a working one in my hand. I understand the "reserve" (which apparently I don't have), I'm also fairly certain I understand "run", but I have no idea what "prime" is. Also, when I and the guy at the shop looked at it, it would spin a full revolution + and never "reach the other setting". How do I know if or what position it is in without a lever? I'm a Newbie sorry.

        Comment

        • tom203
          Forum Guru
          Past Site Supporter
          • Aug 2010
          • 8925
          • Norway,Maine

          #5
          No need to apologize- lots of us don't understand this petcock. In theory, this petcock will only allow fuel to flow if engine is running (makes a vacuum). If fuel has evaporated from carbs (long time sitting) or you've recently installed carbs after a cleaning- you need to get fuel to flow without vacuum since engine ain't running. That's the prime's spot job.Unfortunately, as I understand this thing, even in prime spot you need to burp it ( one vacuum pulse from cranking ) to get things flowing. Hopefully, someone will chime in and correct me!
          1981 gs650L

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

          Comment

          • eil
            Forum Sage
            • Dec 2012
            • 3062
            • SE Michigan

            #6
            tom203, you have it right. I have the same bike and I was confused about this petcock as well.

            If you do need a replacement, CRC2 appears to have brand-new ones for $50 (second one down): http://www.newmotorcycleparts.com/fu...cocks_suz.html

            You can get a rebuild kit for a little cheaper, but there's a thread on here about how the o-ring that comes with it isn't the right size. People here recommend against the rebuild kits, though, for this and other reasons.
            Charles
            --
            1979 Suzuki GS850G

            Read BassCliff's GSR Greeting and Mega-Welcome!

            Comment

            • Nessism
              Forum LongTimer
              GSResource Superstar
              Past Site Supporter
              Super Site Supporter
              • Mar 2006
              • 35790
              • Torrance, CA

              #7
              Details on how the petcock works is in the factory Suzuki service manual. Basscliff has a free download for you if you don't already have it.

              One trick about that petcock is it needs a pulse of vacuum before the prime feature will work.

              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

              • BassCliff

                #8
                Hi,

                Originally posted by David-Z
                ...I'm also fairly certain I understand "run", but I have no idea what "prime" is....
                Read this: Where Do These Hoses Go?

                If you're a newbie and have not received your "mega-welcome, then CLICK HERE. You should find everything you need to save time, save energy, save money, grow your hair, help you lose weight, and improve your love life.


                Thank you for your indulgence,

                BassCliff

                Comment

                • Guest

                  #9
                  Originally posted by Nessism
                  Details on how the petcock works is in the factory Suzuki service manual. Basscliff has a free download for you if you don't already have it.

                  One trick about that petcock is it needs a pulse of vacuum before the prime feature will work.

                  good luck
                  Very important!
                  The only way to prime the float bowls is by sucking on the vacuum line on prime which is the slot in the l position. (up and down) run is parrallel to the ground.

                  Comment

                  • Tom R
                    Forum Mentor
                    Past Site Supporter
                    • Sep 2010
                    • 777
                    • Chicago, IL

                    #10
                    The prime function depends on a little rubber check valve that is supposed to hold diaphragm open once you apply vacuum to it - the run setting opens an air bleed so it only holds the vacuum while it's running. Chances are that check valve doesn't hold after 33 years. As chef said, your best bet to prime that bike is by sucking on the vacuum tube yourself.
                    I've found that once you get the bike running solidly enough, you really don't have to prime it too often.
                    -1980 GS1100 LT
                    -1975 Honda cb750K
                    -1972 Honda cl175
                    - Currently presiding over a 1970 T500

                    Comment

                    • Guest

                      #11
                      I bought a Pingle.

                      Comment

                      • Dogma
                        Forum Guru
                        • Sep 2007
                        • 7143
                        • Mason, OH (SW)

                        #12
                        Originally posted by chef1366
                        Very important!
                        The only way to prime the float bowls is by sucking on the vacuum line on prime which is the slot in the l position. (up and down) run is parrallel to the ground.
                        Or turn the engine over a couple times with it on prime. Give it a few minutes to fill the carbs. Assuming the petcock can still hold vacuum. If it won't you're a candidate for poor flow on run, resulting in starved cabs on the highway. I replaced mine with a new stock unit. Prime it in the spring and forget about it. Put a pingle on it and you need to remember to turn it off when you park it.
                        Last edited by Dogma; 03-19-2013, 09:11 PM.
                        Dogma
                        --
                        O LORD, be gracious to me; heal me, for I have sinned against you! - David

                        Skeptical scrutiny is the means, in both science and religion, by which deep insights can be winnowed from deep nonsense. - Carl Sagan

                        --
                        '80 GS850 GLT
                        '80 GS1000 GT
                        '01 ZRX1200R

                        How to get a "What's New" feed without the Vortex, and without permanently quitting the Vortex

                        Comment

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