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# 1 & 2 not firing

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  • # 1 & 2 not firing

    Bike was running great last year, but started up this spring and #1 cyl not firing. Check the p/u wires (previously repaired) all appears good there. Removed and cleaned the carbs (again). Now both #1 and 2 are not firing (cold header pipes). I pulled the spark plug from #1 and grounded it and there is some spark there but doesn't seem to be consistent. I removed the plug cap and cut off a bit of plug wire and reinstalled the cap. Still no joy. Any ideas? Dennis
    Dennis

  • #2
    No. 1 and 2 carb share a fuel line. I would start there. they do not share spark, so any problem with spark would be a separate problem for each cylinder. Look to the fuel side first.

    Patrick
    The glorious rays of the rising sun exist only to create shadows in which doom may hide.

    XS11F (Incubus, daily rider)
    1969 Yamaha DT1B
    Five other bikes whose names do not begin with "Y"

    Comment


    • #3
      Fuel is getting thru as the plugs are wet. I installed a fresh set of plugs and it fired up on all four as long as I kept the choke (enrichener) on, but soon began to miss badly again.
      Dennis

      Comment


      • #4
        Yep, my bet is a pinched or kinked fuel line, or air bound in line filter something like that.
        Life is what happens while your planning everything else!

        When your work speaks for itself, don't interrupt.

        81 XS1100 Special - Humpty Dumpty
        80 XS1100 Special - Project Resurrection


        Previously owned
        93 GSX600F
        80 XS1100 Special - Ruby
        81 XS1100 Special
        81 CB750 C
        80 CB750 C
        78 XS750

        Comment


        • #5
          If it ran with the enricher on that confirms for me that you have a fuel issue.

          Patrick
          The glorious rays of the rising sun exist only to create shadows in which doom may hide.

          XS11F (Incubus, daily rider)
          1969 Yamaha DT1B
          Five other bikes whose names do not begin with "Y"

          Comment


          • #6
            Hm, I'm confused Patrick, can you explain? I'll check that fuel line again. I've got the fuel running through on Prime as I was getting ready to sync the carbs and the plugs in #1& 2 are wet with gas. I'm running a Uni foam air filter (clean). Snorkel is clear.
            Dennis

            Comment


            • #7
              Well then, if they are wet with fuel, then perhaps you have a flooding issue. Do you have an inline filter to those carbs? Look in the airbox if you have the stock one and see if it has gas laying in it.
              Life is what happens while your planning everything else!

              When your work speaks for itself, don't interrupt.

              81 XS1100 Special - Humpty Dumpty
              80 XS1100 Special - Project Resurrection


              Previously owned
              93 GSX600F
              80 XS1100 Special - Ruby
              81 XS1100 Special
              81 CB750 C
              80 CB750 C
              78 XS750

              Comment


              • #8
                Bike was running great last year, but started up this spring and #1 cyl not firing.
                Did you have gas in the bowls over the winter? If you leave untreated gas in them for a couple months, they'll often get gummed up. Cleaning out the bowls, and the little jets in the bottoms often fixes that. If the bowls were drained, you'll often get a stuck float when you first put gas back to 'em. A rap with the back of a screwdriver on the bowl is usually all it takes to fix that. My $.02
                I think I have a loose screw behind the handlebars.

                '79 XS11 Standard, Jardine 4/1, Dyna DC1-1 Coils, 145 mains, 45 pilots, plastic floats - 25.7mm, XV920 fuel valves, inline fuel filters, speed bleeders, Mikes XS pods, spade-type fuse block, fork brace, progressive fork springs/shocks, manual petcocks, 750 FD, Venture cam chain tensioner, SS brake lines

                Comment


                • #9
                  Well, how red is my face?! I had the fuel supply to #1 & 2 on Reserve and #3 & 4 on Prime. So, yes I did have a fuel issue. Also had the idle screw set waayy too low for the carb bank (after carbs off for cleaning) so of course it wouldn't idle! I figure it was originally been a fouled #1 plug, then I complicated things with the petcock setting when I was getting ready to sync the carbs. Now it's firing on all four, carbs synced....hope to get a test ride in before it rains again! Thanks for the quick feedback, guys!
                  Dennis

                  Comment


                  • #10
                    HOW RED IS IT????!!!!!

                    Just kidding, if we all had a dollar for everytime we thought we had a problem that turned out to be the petcock shutoff, well, some would be richer than others, but we all would be up by at least five bucks.
                    Life is what happens while your planning everything else!

                    When your work speaks for itself, don't interrupt.

                    81 XS1100 Special - Humpty Dumpty
                    80 XS1100 Special - Project Resurrection


                    Previously owned
                    93 GSX600F
                    80 XS1100 Special - Ruby
                    81 XS1100 Special
                    81 CB750 C
                    80 CB750 C
                    78 XS750

                    Comment

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