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Cylinders 2 and 4 running much hotter than 1 and 3?

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    Cylinders 2 and 4 running much hotter than 1 and 3?

    Hey everyone! So some background info.

    Carbs thoroughly cleaned
    New plugs
    Rejetted for pods and 4 into 1 exhaust
    Valves adjusted
    New exhaust gaskets
    New float bowl gaskets
    Adjusted float bowl levels to +-1mm

    Any help? Could it be the point ignition system, or maybe screwing up the valve adjustment? It's my first bike restoration!

    #2
    Spark plug caps are often an overlooked culprit, you could try swapping the two hot ones for the two cold ones as a quick and easy check.
    1980 Yamaha XS1100G (Current bike)
    1982 GS450txz (former bike)
    LONG list of previous bikes not listed here.

    These aren't my words, I just arrange them

    Comment


      #3
      I don't know if I can easily do that as the wires go directly into the coils? Which do you mean to switch?

      Comment


        #4
        Swap the spark plug caps on 2 and #3
        Then, swap #1 and #4

        do they still heat up the same?

        And, your 1980 model has points?
        1978 GS 1000 (since new)
        1979 GS 1000 (The Fridge, superbike replica project)
        1978 GS 1000 (parts)
        1981 GS 850 (anyone want a project?)
        1981 GPZ 550 (backroad screamer)
        1970 450 Mk IIID (THUMP!)
        2007 DRz 400S
        1999 ATK 490ES
        1994 DR 350SES

        Comment


          #5
          The caps pull out of the ends of the wires. It's often suggested to pull the wires out of the caps, clip off about a 1/4 inch of the wire and clean the copper contact that goes into the cap and reassemble. On my bike that contact was a straight piece so it's a good idea to pull and reinsert them with as little twisting as possible.
          1980 Yamaha XS1100G (Current bike)
          1982 GS450txz (former bike)
          LONG list of previous bikes not listed here.

          These aren't my words, I just arrange them

          Comment


            #6
            Would not be the coils (nor pickup) since one coil services 1&4 and other coil services 2&3.

            I would more suspect the carbs..... or the plugs ...... or the plug caps as mentioned.
            THe caps do deteriorate over the miles.
            Can get new ones for about $5 each or less.
            1&4 are the same and 2&3 are the same part number, the difference is only overall length and angle.
            Can also Ohm check them with a meter (resistance), should be right about 5K ohms each. When they are going bad they go way higher ohms and then go completely open (infinite ohms).

            Could swap 1 with 4, and 2 with 3, as something of a test.
            Like said before, hold onto wire, pull twist unscrew and pull off the cap. Look and see if all the strands of wire (not really wire) are there yet, if some are burnt-broke-missing you can trim off about 1/4-3/8th inch of the wire to get to fresher strands.
            Last edited by Redman; 12-14-2019, 08:29 PM.

            Had 850G for 14 years. Now have GK since 2005.
            GK at IndyMotoGP Suzuki Display... ... GK on GSResources Page ... ... Euro Trash Ego Machine .. ..3 mo'cykls.... update 2 mocykl


            Comment


              #7
              So it turns out, that the guy i bought it from had the coils in the wrong way. The left side was hooked up to 1 and 2, and the right side was 3 and 4!

              Who would have thought it wouldve even started from that!

              Bike runs like a dream now Thanks for all the help guys!

              Redman I'm going to take apart the cables and replace the caps, cables too worth it? It's a good preventative maintenance thing it seems especially because they look like they've seen better days!

              Comment


                #8
                I can’t even imagine the bike even running that way. Must have sounded horrid. Glad you got that sorted.
                Rich
                1982 GS 750TZ
                2015 Triumph Tiger 1200

                BikeCliff's / Charging System Sorted / Posting Pics
                Destroy-Rebuild 750T/ Destroy-Rebuild part deux

                Comment


                  #9
                  Easssssch.... It will? run like that?
                  Guess so.

                  Originally posted by Zaos View Post
                  . . .
                  ....
                  .....
                  Redman I'm going to take apart the cables and replace the caps, cables too worth it? It's a good preventative maintenance thing it seems especially because they look like they've seen better days!
                  Cables? Spark Plug Wire I assume.

                  THey would have to be real bad to be worth replacing. THe caps come off the wires easy. But the wires dont easily come out of the coils. THey are fixed in with epoxy or something. Some folks have replaced them but it isnt easy. WHat is easy is to damage the connection inside the coil while trying to replace the wire.

                  Had 850G for 14 years. Now have GK since 2005.
                  GK at IndyMotoGP Suzuki Display... ... GK on GSResources Page ... ... Euro Trash Ego Machine .. ..3 mo'cykls.... update 2 mocykl


                  Comment


                    #10
                    The other hard portion is finding the right size wire. I dont know the specifics but have seen such discussions here.
                    7mm verses 8mm verses 1/4inch or something like that.

                    Had 850G for 14 years. Now have GK since 2005.
                    GK at IndyMotoGP Suzuki Display... ... GK on GSResources Page ... ... Euro Trash Ego Machine .. ..3 mo'cykls.... update 2 mocykl


                    Comment


                      #11
                      Originally posted by Zaos View Post
                      So it turns out, that the guy i bought it from had the coils in the wrong way. The left side was hooked up to 1 and 2, and the right side was 3 and 4!

                      Who would have thought it wouldve even started from that!

                      Bike runs like a dream now Thanks for all the help guys!

                      Redman I'm going to take apart the cables and replace the caps, cables too worth it? It's a good preventative maintenance thing it seems especially because they look like they've seen better days!
                      LOL, love the easy fixes! well done.
                      -Mal

                      "The only reason for time is so that everything doesn't happen at once." - B. Banzai
                      ___________

                      78 GS750E

                      Comment


                        #12
                        Yeah the bike sounded like it was dying, but it still did rev a bit.

                        I'll check out the caps and take them apart, clean them up and check for any cracks in the rubber. Should clean up good enough!

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