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    Gs850 valve clearance question

    Hi - have been sourcing new shims for my 850 which I don't think has been done before in its 20k lifetime.
    Having to replace all 8 shims for thinner ones. Last 2 to source for #4 should have been a 2.55 and a 2.30 - but accidentally ordered a 2.25 and a 2.50.
    My question is Will an 850 run ok (ie without damaging anything) if valve clearance is 0.12/ 0.13 or have I just spent £30 on spares I won't need for a while.
    On a side note - I do have some larger shims going spare - am unable to measure a few as number is worn off tho.

    #2
    I have heard of people going all the way up to .10 with clearance in the exhaust side. Apparently the exhaust wears faster. My understanding is looser is better than too tight. Of course you can go too loose and the valve will not open all the way. Can you do any swapping around with the other shims to bring it down a little ?

    Comment


      #3
      Those clearances are a bit beyond what some of us usually run, but they will not hurt the bike.

      .
      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
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      Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
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        #4
        Measure all the shims. Don't take the number on it at face value. People have been known to grind them down.
        97 R1100R
        Previous
        80 GS850G, 79 Z400B, 85 R100RT, 80 Z650D, 76 CB200

        Comment


          #5
          It'll be fine. These are still tiny, tiny measurements. You won't even be able to hear a difference.

          Most bikes with this shim over bucket arrangement specify much larger valve clearances than the GS. For example, the KLR650 specs .10-20mm for the intake valves and .15-.25mm for the exhaust valves.
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            #6
            Thanks for the replies.
            Unable to reuse any previous shim due to all being too tight.
            Took a chance and bought a brand new 2.30 first and then measured using this shim in each valve (one thing I do have is time lol). Think I got overexcited as it was the last two to get!

            Comment


              #7
              Originally posted by bwringer View Post
              It'll be fine. These are still tiny, tiny measurements. You won't even be able to hear a difference.

              Most bikes with this shim over bucket arrangement specify much larger valve clearances than the GS. For example, the KLR650 specs .10-20mm for the intake valves and .15-.25mm for the exhaust valves.
              That's interesting. What is the redline for the KLR? I assume it's lower than a GS. Main concern with going with too much clearance is for fear of spitting a shim at high RPM's.

              The KZ1000 models use an upper shim limit of .15 so going that high should be no concern for a GS.
              Last edited by Nessism; 06-27-2016, 11:03 AM.
              Ed

              To measure is to know.

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                #8
                Originally posted by Nessism View Post
                Main concern with going with too much clearance is for fear of spitting a shim at high RPM's.
                I have measured the depth of the recess in the bucket, and found that it is almost 2mm, so spitting a shim should not be a problem, as long as you keep it out of the red zone.

                .
                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


                  #9
                  Originally posted by Nessism View Post
                  That's interesting. What is the redline for the KLR? I assume it's lower than a GS. Main concern with going with too much clearance is for fear of spitting a shim at high RPM's.

                  The KZ1000 models use an upper shim limit of .15 so going that high should be no concern for a GS.
                  my 81 kz1000m1 specifications were actually a lot closer to a gs's specifications than that. I think upper limit is around .09. i'll try to remember to confirm when I go to the storage unit again this weekend.

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