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    Valve clearance questions

    I opened up the engine and checked my valve clearances. Most of them are around 0.03 so that means i need to replace the shims right? How do i know what size shims i currently have and which new ones should i get?

    #2
    The clearance decreases with miles, so all those .03mm clearance valves should move to thinner shims.

    Remove each shim, and read the thickness numbers on them. Have a set of calipers handy, because sometimes the numbers wear off the shims. Keep a notebook log of each shim size. And never rotate the engine without a shim installed. The cam will be damaged.

    Lastly, be sure to follow the Suzuki valve clearance adjustment method for cam position. Pointing the cam lobe away from the bucket will lead to the clearance showing more clearance than actually is the case. Actually, you can use this method, but bump your minimum clearance range up to .05mm.

    Suzuki's spec of .03-.08mm is needlessly tight. You can easily, and safely, run clearance up to .12mm. Kawasaki KZ engines run to .15mm, and they don't spit shims out, so a GS engine can surely run more than .08.
    Last edited by Nessism; 07-30-2025, 09:57 AM.
    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

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      #3
      The procedure is in the factory service manual. If you tell us the year and model, we can point you to a free one. Always important to have a manual.
      Rich
      1982 GS 750TZ
      2015 Triumph Tiger 1200

      Comment


        #4
        Use the Zip-Tie method.
        The factory approved tool is a piece of crap, just waiting to damage itself or you.
        Dave
        '79 GS850GN '80 GS850GT
        Only a dog knows why a motorcyclist sticks his head out of a car window

        Comment


          #5
          Another vote for the zip-tie method.

          Also want to add a caution: be careful of your measuring units. You mention that your clearances are "around 0.03", but did not mention the units. I would presume you are using sillymeters. The caution comes if you are using INCHES, because 0.003" would be (near) the maximum clearance, while 0.03mm is the minimum clearance.

          Send me a PM that includes your e-mail address, I'll send you a copy of my spreadsheet that will help you determine what shims you will need.

          .
          sigpic
          mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
          hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
          #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
          #2 son: 1980 GS1000G
          Family Portrait
          Siblings and Spouses
          Mom's first ride
          Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
          (Click on my username in the upper-left corner for e-mail info.)

          Comment


            #6
            Third vote for the zip-tie method. This is the way. I use a zip tie to hold the valve open, and a small screwdriver with a magnet on the end to "suck" the valve out of the seat. Couldn't be easier.

            And get the spreadsheet Steve is offering. Not only does it make it easy to see what shims you need, but it's helpful to keep track of them over time. You should be checking valve clearances ever 5-7k as per the service manual.

            Comment


              #7
              To Ray1234, a pdf on the The Zip tie method referred to above, and service manuals can be found on BikeCliff's Website.

              Bookmark this valuable resource.

              The manuals are in the top section in the middle.
              The zip-tie method and a stand-alone pdf for Valve adjustment are in the next section on the left hand side. Or follow these links below.
              If you have even the least ability to use microsoft excel, take Steve up on his offer for his spreadsheet. You'll still need to take out and measure your shims one-by one. But the spreadsheet will do the math for you to figure out what shims you'll need or can maybe swap.
              Valve Adjustments (8 Valve)
              Zip Tie Supplement

              And like Steve mentioned, to avoid mistakes and misunderstanding, always include units (mm or inches) when mentioning clearances. ​
              Last edited by Rich82GS750TZ; 07-31-2025, 08:51 AM.
              Rich
              1982 GS 750TZ
              2015 Triumph Tiger 1200

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