"Loose" intake valve clearances

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  • norman1950
    • Feb 2026

    #1

    "Loose" intake valve clearances

    Bare with me on this, as I am a newbie to working on Valves. Since the bike is torn down thought it would be a good idea to check the valve shim clearances. In doing so I have printed out the Valve shim sheet and noted all my clearances and what current shims are in the bike.

    So my real question is on #3 and #4 intake valves, the clearances are .007" with both having shims of 2.45. Is there something I need to worry about with that much clearance or just get a 2.50 shim for each valve.

    Just for reference here is how everything measured out and the shims

    ....................................Exhaust
    Gap .002............Gap .003............Gap .0015...........Gap .003
    Shim 2.65...........Shim 2.60...........Shim 2.60............Shim 2.55x

    ......#1....................#2.................... #3.....................#4

    ....................................Intake
    Gap .004............Gap .003............Gap .007............Gap .007
    Shim 2.60...........Shim 2.55x.........Shim 2.45...........Shim 2.45



    Thanks for helping a newbie out
    Last edited by Guest; 08-16-2013, 05:00 PM.
  • ozman

    #2
    to start id swap exhaust 1 and 3 then recheck what you need for exhaust 3
    recheck ex 1 while your going
    ozman

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    • jsandidge
      Forum Sage
      Past Site Supporter
      • Jun 2013
      • 1482
      • Norfolk, Virginia

      #3
      The specs call for a range between .003 to .008. Oz is right, your intakes are in spec, but you're tight on exhaust 1 & 3.
      https://drive.google.com/open?id=0B9zH8w8Civs8ejBJWjdvYi1LNTg&resourcekey=0-hlJp0Yc4K_VN9g7Jyy4KQg&authuser=fussbucket_1%40msn.com&usp=drive_fs
      1983 GS750ED-Horsetraded for the Ironhead
      1981 HD XLH

      Drew's 850 L Restoration

      Drew's 83 750E Project

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      • earlfor
        Forum LongTimer
        Charter Member
        GSResource Superstar
        Past Site Supporter
        • May 2002
        • 42413
        • off grid cabin 1/24/26 7pm

        #4
        Exhaust valves get hotter than intake valves. I always set my exhaust with more clearance than the intakes.
        Komorebi-The light filtering through the trees.

        I would rather sit on a pumpkin and have it all to myself than be crowded on a velvet cushion. H.D.T.

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        • ozman

          #5
          Originally posted by earlfor
          Exhaust valves get hotter than intake valves. I always set my exhaust with more clearance than the intakes.

          very good advice there i like 0.06 to 0.08 on exhausts for that reason
          0.04 to 0.06 on inlets
          i talk in mm not imperial thou

          ozman
          Last edited by Guest; 08-16-2013, 09:16 PM. Reason: left out the decimal point !

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          • 1980GS1000E
            Forum Sage
            Past Site Supporter
            • Aug 2007
            • 1665
            • San Diego, California, USA

            #6
            I like to run max clearance to be on the safe side.
            Current Rides: 1980 Suzuki GS1000ET, 2006 H-D Fatboy, 2021 BMW K1600B

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            • cowboyup3371
              Forum LongTimer
              Past Site Supporter
              • Apr 2010
              • 13996
              • In Ohio Now

              #7
              Have you emailed Steve for his spreadsheet yet?
              Cowboy Up or Quit. - Run Free Lou and Rest in Peace

              1981 GS550T - My First
              1981 GS550L - My Eldest Daughter's - Now Sold
              2007 GSF1250SA Bandit - My touring bike

              Sit tall in the saddle Hold your head up high
              Keep your eyes fixed where the trail meets the sky and live like you ain't afraid to die
              and don't be scared, just enjoy your ride - Chris Ledoux, "The Ride"

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              • Steve
                GS Whisperer
                • Jun 2005
                • 35925
                • southwest oHIo

                #8
                Originally posted by jsandidge
                The specs call for a range between .003 to .008. Oz is right, your intakes are in spec, but you're tight on exhaust 1 & 3.
                BE VERY CAREFUL WITH THIS ADVICE.

                The proper clearance specifications are 0.03 to 0.08 mm. Note that there is only ONE zero between the decimal and the first non-zero number.

                If you are using INCH measurement devices, the specifications are 0.0012 to 0.0031". Note that there are two zeros between the decimal and the first non-zero number.

                It is also very important to note that there is a number 3 in both sets of specs, but one is for maximum clearance, the other is for minimum clearance.

                Norman, I would switch your #3 and #4 intakes to 2.55s, and your #3 exhaust to 2.55, assuming that you are using INCH measurements.

                .
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                • norman1950

                  #9
                  Originally posted by Steve
                  BE VERY CAREFUL WITH THIS ADVICE.

                  The proper clearance specifications are 0.03 to 0.08 mm. Note that there is only ONE zero between the decimal and the first non-zero number.

                  If you are using INCH measurement devices, the specifications are 0.0012 to 0.0031". Note that there are two zeros between the decimal and the first non-zero number.

                  It is also very important to note that there is a number 3 in both sets of specs, but one is for maximum clearance, the other is for minimum clearance.

                  Norman, I would switch your #3 and #4 intakes to 2.55s, and your #3 exhaust to 2.55, assuming that you are using INCH measurements.

                  .
                  Yes I was using inch measurements. I should have stated that earlier.

                  Ok good at least my thinking was similar to yours. I was just over thinking it.

                  Thank you all for your inputs.

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                  • norman1950

                    #10
                    Got the shims, now to find time to go to the shop and check clearances.

                    Thanks again for all the help, will report back shortly.

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