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  • Valve Clearance Advice

    79sf, 23k miles

    E1: .008
    E2: .008
    E3: .008
    E4: .008

    I1: .003
    I2: .004
    I3: .006
    I4: .003

    Intake Spec: .006-.008
    Exhaust Spec: .008-.010

    I don't know if any previous owners ever performed any valve adjustments, but the bike obviously needs one, which I will do regardless.

    Few questions:
    1. Remove the cams or use the tool?
    2. Should their be a noticable performance/efficiency increase afterwards?
    3. How much time should I set aside for the job (first time)?
    4. They provide a "range" for clearances. Anyone know what a brand new XS off the factory line would have been set at? I.e., .008 for intake and .010 for exhaust? I'm considering setting clearances at max, unless that's a bad idea.

    Any other comments about these clearances and their affect on the way my bike runs are welcome.

    Ben
    Last edited by Shuriken; 06-10-2007, 07:24 PM.
    1985 Yamaha VMX12n "Max X" - Stock
    1982 Honda XL500r "Big Red" - Stump Puller. Unknown mileage.
    1974-78 Honda XL350 hybrid - The thumper that revs. Unknown miles.
    1974 Suzuki TC/TS125 hybrid. Trials with trail gear. Invaluable. Unknown miles.
    1971 Honda CL350. For Dad. Newtronic Electronic Ign. Reliable. Unknown miles.

    Formerly:
    1982 XS650
    1980 XS1100g
    1979 XS1100sf
    1978 XS1100e donor

  • #2
    Use the tool and use it with care . Read the instruction fully and carefully.
    Will run quieter when done but I never noticed any performance increase for the sake of doing just the valves. That might be different if they are not fully closing but if that was the case they would have got burned and would not seat fully even after an adjustment. Carb tune up will improve performance.
    Not sure how much time to set aside... everyones skill level is different.
    Manual says to set they as close to smallest spec as you can = less top end noise. I find that making them all as close to each other as possible is also quieter.
    Your EX numbers are good so leave them as is.
    Rob
    KEEP THE RUBBER SIDE DOWN

    1978 XS1100E Modified
    1978 XS500E
    1979 XS1100F Restored
    1980 XS1100 SG
    1981 Suzuki GS1100
    1983 Suzuki GS750S Katana
    1983 Honda CB900 Custom

    Comment


    • #3
      Hey Ben,

      As for performance, would depend on whether you are keeping the exhaust valves open when the engine warms up with those close values?? You might try a compression test cold and then again warmed up! If it's the same or higher when warm, then you probably haven't burned any valves, but if it's lower, then you might have started to burn them. Also lower when warm could affect performance, and so you might get a little boost with the proper clearances....possibly more noticeable in MPG than seat of the pants!?

      Dangit, just realized was looking at the wrong valves, Ex instead of intake!
      The shims come in .05mm increments which is ~.002 in., so going about 2 steps thinner on 1,2, and 4, and 1 step thinner on #3 would set you at:
      ~.007in; .008in; .008in; .007in IF my calculations are correct?!
      I remember posting a valve shim calculator, but you need to know what size shim is in there!!

      Technique will be what you are capable of and feel most comfortable with. Both will take time, but the valve tool would probably be the safer of the two. You'll need to switch it among the valves a few times, once to find out what shim are there, and then to determine IF you can swap any between cylinders? You may still need an extra one, won't matter what it's size, just to put in the lifter bucket if you need to rotate the cams, you don't want to have the cam rubbing directly against the bucket innards!

      Probably allow a few hours, but may be less depending on how far it is to the shop to get the required shims, unless you've gotten a set already?
      T.C.
      T. C. Gresham
      81SH "Godzilla" . . .1179cc super-rat.
      79SF "The Teacher" . . .basket case!
      History shows again and again,
      How nature points out the folly of men!

      Comment


      • #4
        My vote is to do them all while you're in there. You're at the very bottom of the "In Spec" on the exhaust. Just do them all now so you don't have to worry about again it in six months..

        Also.. for me it's easier to just pull the cams. But, I've done it several times and the tool I bought wasn't worth a crap.. so.. Just my 2 cents.


        Tod
        Try your hardest to be the kind of person your dog thinks you are.

        You can live to be 100, as long as you give up everything that would make you want to live to be 100!

        Current bikes:
        '06 Suzuki DR650
        *'82 XJ1100 with the 1179 kit. "Mad Maxim"
        '82 XJ1100 Completely stock fixer-upper
        '82 XJ1100 Bagger fixer-upper
        '82 XJ1100 Motor/frame and lots of boxes of parts
        '82 XJ1100 Parts bike
        '81 XS1100 Special
        '81 YZ250
        '80 XS850 Special
        '80 XR100
        *Crashed/Totalled, still own

        Comment


        • #5
          I'm considering setting clearances at max, unless that's a bad idea.
          When I'm adjusting the clearances,
          I shoot for getting them all as near the lower of the spec as possible.
          Exhaust is "spot on" at .008
          as is intake #3 at .006


          mro

          Comment


          • #6
            "Might take about an hour, maybe a little more"

            Clean the oil offa the intake cam gear.
            Take some fingernail polish... mark a link of the chain and the cam gear for quick reference in case the chain jumps offa the gear.
            Set the timing plate to the "C" position
            Pull the cam chain tensioner off.
            You have three shims to do on the intake, much quicker to just lift up the cam to access the shims.
            Intake #3.. If it's a tight .006, maybe I'd change it. If it's a loose .006, I'd leave it alone.
            "Damn it Jim, I'm a doctor, not a mechanic!' ('Bones' McCoy)

            Comment

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