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  • Gas Fouling and Idle Problems

    Hi everybody. I'm a newbie to the Forum. I'm having two different but possibly related problems with my "new" old bike.
    My plugs gas fouling and my idle speed.

    69 FLH
    S&S Super E Shorty 70 Main 280 Intermediate (I'm at 6200 ft)
    Andrews J
    8.5:1
    V-Twin late model long reach heads (new) (long story)
    Autolite 66 plugs (a little hotter for the late heads?) @ 30
    New coil,plug wires (non-resistor), points (@ 20) and condenser
    Static timed only at 35 dgrees

    If I put in new plugs it will start in 4 or 5 kicks and I can ride about 15 or 20 city miles before it starts missing. When I pull the plugs they're dry black and sooty, I tried a smaller jets but it coughs and chokes at higher rpms (just before the shift point) so I put the 70 back in (left the 280) and I've adjusted the accelerator pump from black smoke out the pipes to no pump at all with no change. I've tried 2 different carbs jetted and adjusted the same and it still has the same problems. Is it possible that the ignition system is too "weak" to fire the late model electronic ignition plugs properly?

    And

    after it's warmed up I can only get it to idle at about 12-1300 if I back out the screw an 1/8 of a turn more it slows and dies. Again the same thing with 2 different carbs. Is it possible the advance weight springs are too "weak" causing it to snap back to full retard too quickly?

    Any ideas???

    Thanks in advance
    Steve

    P.S. While I know it may not be feasible I would love to see the Shovelhead section split into three sections,
    Generator, Nose cone points and nose cone electronic. It sure would make searching a lot easier as they are just different enough that what works on one may not be applicable to the others. Just my 2 cents!!!

  • #2
    Steve!

    It could be all, some, or none of those things.

    Please pressuretest your manifold first to be certain you haven't over-enrichened to make up for a vacuum leak, or you may chase your tail.

    ....Cotten
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

    Comment


    • #3
      I know of four Panheads in the Denver area [5300 ft.] that run 70/28 with good results.
      Is your coil ohm rating correct for your points?
      VPH-D

      Comment


      • #4
        if you're running points you need a 4+ ohm coil---i think you should run 295 intermediate with 70 main. when you adjust the low mix on the brass screw at an angle on top of carb turn it in until the motor misses then back out 1/8 to 1/4 turn. if you don't do it in sequence like this you will never get to idle right. then last you turn in the accelerator pump screw until it has a hesitation when you blip the throttle. then you back out the acc pump screw until the hesitation goes away. if you do all this and still have black smoke the only other thing that will cause it is the float level is too high. keep in mind that even though it appears to be adjusted right it could still be too heavy and sinking into the gasoline too far. the fuel today has too much ethanol in it and you might have to replace the float with the new type. if the carb is new it should already have it. do the adjustments first though. good luck

        Comment


        • #5
          Originally posted by flat-happy View Post
          the fuel today has too much ethanol in it and you might have to replace the float with the new type.
          Any mixed-in ethanol is too much; It should be reserved to burn in dedicated straight ethanol motors, like mass transit applications, etc.
          That would make too much sense, however.

          But it is interesting to know that the modern carb world had to change formulations too!

          ...Cotten
          Meanwhile, I hope Steve doesn't overlook a lit fuse.
          AMCA #776
          Dumpster Diver's Motto: Seek,... and Ye Shall Find!

          Comment


          • #6
            XLCH72,
            As far as Sub-Categories go-
            I know interest in Shovelheads will continue to grow, however right now the 35 year cut-off makes all 80ci and all electronic ignition models outside the realm of this club. There are plenty of other forums that go into detail on those models. Many members of this club use those. But there is no reason at this point to even consider sub-categories. To me at least and I am sure other members of this club, a Shovelhead is some sort of modern motorcycle that is of no major interest. Don't even start on Evos and Twinkies! Lets try to keep the AMCA site for what it is intended. Antiques as defined by the club. And that is just my 2 cents!
            Robbie
            Robbie Knight Amca #2736

            Comment


            • #7
              Robbie!

              Please take it from one vinegary curmudgeon to another,
              it was a skosh callous to call Chubbleheads of "no major interest"!

              Everybody but me seems to have one!
              (Perhaps that implies that congenitally I'm missing an orifice; No doubt the rest of me made up for it..)
              So, I've plenty of opinions, thus..

              The manufacturing world changed greatly in the Seventies, and those Enthusiasts who pick up the standard for the AMCA reason-to-be must offer changes of judging perspective that are equally dramatic.

              I wish them perserverance and good luck, as plastic is very unfriendly in the long run.

              ....Cotten
              AMCA #776
              Dumpster Diver's Motto: Seek,... and Ye Shall Find!

              Comment


              • #8
                Will try on Sunday

                Thanks for the ideas. I'll try them on Sunday starting with the leak test. Gonna have to use the standby leak test (spray the manifold while running) then go from there. Coil tested at 5.something so thats been eliminated. Will keep advised of progress.

                Thanks again
                Steve

                PS I agree wholeheartedly with Rub on the clubs intent but, in a few short years (4 if my math is right) our non-points bretheren will be eligible under the 35 year rule.

                Comment


                • #9
                  Originally posted by xlch72 View Post
                  Gonna have to use the standby leak test (spray the manifold while running) then go from there.
                  Please beware, Steve,
                  That spraying combustibles around a running motor is not only un-safe, it will only display large leaks.

                  Tiny leaks put holes in pistons.

                  ....Cotten
                  AMCA #776
                  Dumpster Diver's Motto: Seek,... and Ye Shall Find!

                  Comment


                  • #10
                    i've had good luck spraying with WD40 while the engine is idling. it will make the engine quit with the tiniest leak and easy to clean up. PJ 1 from the harley dealer works even better but more folks are apt to have WD40 on hand.

                    Comment


                    • #11
                      gas fouling

                      i put a set of vtwin heads on a 68 shovel for a guy last year and never could get it to run decent. same problem as you. finally opened up the mufflers and leaned it as much i could it still did,nt have enough power to pull a greasy string out of a cats butt good luck. t- bone

                      Comment


                      • #12
                        Flat, isn't PJ-1 an aerosol chain lubricant? I'd never thought of using something like that before.........

                        Comment


                        • #13
                          PJ-1 makes several products----i use the professional grade contact cleaner for the leak test because there is no cleanup and you can spray it on anything including windshield paint and seats without damage.

                          Comment


                          • #14
                            Unless I'm mistaken, the combustible element in WD-40 was eliminated a few years ago. Brake and Carb cleaners, on the other hand, mostly still carry the "danger, extremely flammable" warning and associated pros and cons.

                            Also, especially when spraying the manifold from the left side, it's easy to apply too much and have it sucked into the air cleaner, causing a "false positive" belief there's a manifold or manifold seal leak.
                            Ride it like you can fix it!

                            Comment


                            • #15
                              You guys are missing the point about spraying crap while the motor is running.

                              IT DONT ALWAYS FIND THE LEAK.

                              Bubbles don't even need the carb on the motor, much less have it warmed up to thrash it through some RPMs.

                              But that's how you break in a fresh motor, right? (And some Bon Ami cleanser!)

                              Would you want your doctor to smell your armpits to tell if you have cancer?

                              I've a good buddy who uses a CO2 fire extinguisher.
                              Half the time he can tell which side of the bike the leak is on.

                              ....Cotten
                              AMCA #776
                              Dumpster Diver's Motto: Seek,... and Ye Shall Find!

                              Comment

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