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Valve shimming question

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  • Valve shimming question

    so after rebuilding an xj1100 from the ground up i finally got my cam chain tensioner in today so i got all the timing down and after that i started the valve shim. the intake valves however have almost no clearance. i also rotated the whole cam thinking that maybe i had the cam lobe in the wrong position but even to the eye i could not see a shimmer of light. and specs call for between .16-.20 mm of clearance. another thing is that when i pulled the head off i recorded all of the lifter pad and the exhaust and intake are all almost identical like it intake lifter pad for cylinder one is 285 along with the exhaust pad. also i remember but did not record almost all of the valve springs where about the same length and all in spec. i'm just trying to figure out if maybe the PO increased the lifter pad as of a mistake of not realizing he had 4 bent intake valves the whole reason i pulled the head off in the first place. also before i started working on it this winter i rode it around after i replaced the valves and the bike was running pretty rich and the idle setting screw was almost tightened down could this be cause the lack of clearance in the intake valves giving the engine more fuel then it should? i just want to ask the 1100 gods before i start buying smaller pads

  • #2
    Well, for starters, on the XJ, the intakes are shimmed to .11~.15mm and exhaust is .21~.25mm.

    You will need to get the thinnest shims you can find to give you a place to start. If you replaced the valves, the clearances the old valves had won't be anywhere near the same. Did you lap the new valves?


    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


    • #3
      Secondly the "idle screw" does not have anything to do with the valve clearance. The thickness of the valve shims can only affect the valve clearance.
      BDF Special
      80SG Vetter bagger 1196 Wiseco big bore kit, Mega Cycle Cams, slotted cam gears, ported and flowed head, bronze intake seats, Dyno Jet kit, Dyno coils and Mikes XS air pods, Venture cam chain adjuster,Geezer's regulator, Clutch mod, Mac 4 into 1 with custom built and tuned baffle, Oil cooler,MikesXS emulators mod.
      Dyno tuned to 98 hp at the rear wheel.

      Comment


      • #4
        yes i did lap the valves and now that you say that it makes perfect sense also tin man i was just saying about the idle mixture screw cause the bike was running super rich and if the valve is letting in more fuel wouldn't that cause it to run richer then it is suppose to

        Comment


        • #5
          Running rich could be lots of things, from the mixture screws, to the float levels, clogged jets, float needles not seating...

          From the factory, those carb mixture screws were capped off. Apparently someone has removed that cap over the years? Did you leave the YICS tube intact? You'll need the YICS tool to sychronize the carbs if that's the case.


          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


          • #6
            One more correction - there are no 'gods' here. Most of us are just regular joes that play mechanics on the internet. There are some pros here, though.

            Comment


            • #7
              Pros VS Joes.

              Hi. My name is Joe.


              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

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