Announcement

Collapse
No announcement yet.

New Bike No Spark

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • New Bike No Spark

    Well I made it down to Fl to help John Doe work on his 78. This bike is one of the cleanest machines of its age I have ever seen.



    It has its issues, turn signals missing, stock exhausts cut off and wielded to the collectors, came to us with all the brake pads in a box, battery box hold down brackets missing. With the exhaust we will get creative, maybe HD mufflers or something along that line. The rest of the stuff can be had from the spare parts bin. That was the stuff you could see. First step of course was pull the carbs so 15 min later we knew what our day was going to be. We discovered that the stock air filter had been replaced with a rock catcher piece of screen so a air filter is on order now. 10 years of fuel sitting in the bowls was not a pretty thing.





    couple of hours of cleaning later and a couple of full rebuild kits we were ready to set the floats. During the cleaning process we found 2 of the floats had holes corroded in the bottoms. Out came the soldering iron and many beers later they no longer leaked air when put in hot water.



    Obviously soldering is not a highly developed skill in our case. Problem I have is the balance has been affected and they no longer float level. I have a set of good floats in the parts pile in NC so a call to Salty Dog and the FedEx machine will have them here by Tue. So we sat the carbs aside and drained the 10 year old oil and pulled the filter. It was just this side of crude and the filter looked like it was about to come apart in my hands. It will take a couple of oil changes to flush this one out. Doug had pulled the plugs and given each cylinder a shot of marvel mystery oil when he brought it home 2 weeks ago. It rolls over nicely and compression is good. Now on to checking for good spark on all four. Nothing, nadda zip. No spark at all. We went to the fuse box and had to replace a couple of clip and now have that working as it should. I checked for power at the TCI and have 12 volts on the input wire. I checked the 12 volts to the coils and have 12 volts on one set of coils but nothing on the other. This is my first experience with the bias resistor system. Looking for suggestions as to what to look for next. I have a TCI that came from the Element which is an unknown but Salty is shipping that south with the floats.
    Last edited by Ken Talbot; 03-06-2011, 09:30 PM. Reason: image layout
    wingnut
    81 SH (Daily Ride)
    81 650XJ (Brother in laws bike, Delivered)
    81 650XJ Jane Doe (Son's Ride)
    82 750XJ Project bike (Son in law's future ride)
    81 XS 400

    No man has a natural right to commit aggression on the equal rights of another; and this is all from which the laws ought to restrain him.”

    A government big enough to give you everything you want, is strong enough to take everything you have.

    Thomas Jefferson

  • #2
    If you have 12 volts to one but not the other it is a wiring issue. The same wire feeds both coils but splits up by the coils.
    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


    • #3
      Originally posted by DGXSER View Post
      If you have 12 volts to one but not the other it is a wiring issue. The same wire feeds both coils but splits up by the coils.
      Maybe, maybe not...

      He's right in that 12 volts is fed to the coils by one wire through the red/white wire. The TCI unit then switches the other two to ground to fire the plugs. Check to see if you have 12 volts at both coils on the R/W to a frame ground; if you do, the problem is probably in the TCI unit. You shouldn't have 12 volts across the two primary coil connections if the bike isn't running; if you do, you may have a bad diode in the TCI.
      Fast, Cheap, Reliable... Pick any two

      '78E original owner - resto project
      '78E ???? owner - Modder project FJ forks, 4-piston calipers F/R, 160/80-16 rear tire
      '82 XJ rebuild project
      '80SG restified, red SOLD
      '79F parts...
      '81H more parts...

      Other current bikes:
      '93 XL1200 Anniversary Sportster 85RWHP
      '86 XL883/1200 Chopper
      '82 XL1000 w/1450cc Buell, Baker 6-speed, in-progress project
      Cage: '13 Mustang GT/CS with a few 'custom' touches
      Yep, can't leave nuthin' alone...

      Comment


      • #4
        Those are some nasty looking carbs!
        Nathan
        KD9ARL

        μολὼν λαβέ

        1978 XS1100E
        K&N Filter
        #45 pilot Jet, #137.5 Main Jet
        OEM Exhaust
        ATK Fork Brace
        LED Dash lights
        Ammeter, Oil Pressure, Oil Temp, and Volt Meters

        Green Monster Coils
        SS Brake Lines
        Vision 550 Auto Tensioner

        In any moment of decision the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing.

        Theodore Roosevelt

        Comment


        • #5
          Well just for grins I started checking the coils. I know, why would both coils go bad at the same time. Following the book the primary side of both check out good. The secondary side on both were way out of spec. I pulled the caps and they checked out good. We decided to do a coil wireectomy. Cut the plastic on the first coil and measured the windings at the pins and it checked out right at the spec. So far so good. Now the search begins for 6mm copper core wire. The original wires were very stiff and even with clipping the ends a 1/4 inch still measured either open or high in the K ohms scale. Ten years is a hot shed in Fl must have taken its toll. No one in town here in Melbourne had what we needed. Any one have a source for these wires?
          wingnut
          81 SH (Daily Ride)
          81 650XJ (Brother in laws bike, Delivered)
          81 650XJ Jane Doe (Son's Ride)
          82 750XJ Project bike (Son in law's future ride)
          81 XS 400

          No man has a natural right to commit aggression on the equal rights of another; and this is all from which the laws ought to restrain him.”

          A government big enough to give you everything you want, is strong enough to take everything you have.

          Thomas Jefferson

          Comment


          • #6
            Aren't the oems 7mm?
            Nathan
            KD9ARL

            μολὼν λαβέ

            1978 XS1100E
            K&N Filter
            #45 pilot Jet, #137.5 Main Jet
            OEM Exhaust
            ATK Fork Brace
            LED Dash lights
            Ammeter, Oil Pressure, Oil Temp, and Volt Meters

            Green Monster Coils
            SS Brake Lines
            Vision 550 Auto Tensioner

            In any moment of decision the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing.

            Theodore Roosevelt

            Comment


            • #7
              Well,

              I just went out and measured mine, and they were 7mm, but the coil had a
              4H7 number/prefix, haven't checked to see what the # for the 78-79 coils are. It's suggested that folks just STRIP back the insulation just enough to allow the ends to either fit into the OEM coils, or the plug caps.

              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

              Working...
              X