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    No spark on any cylinder

    Hey all,

    Working on Resurrecting at 79 GS1000E. After cleaning up the inside of the ignition switch and wiggling the fuses around, i managed to get the oil/neutral light to come on and the bike will turn over. However, it would not start. I removed a plug and when inserting the loose plug in each spark plug wire end, I see no spark at the gap for any of the 4 plug wires. What are some things to check?

    Also, when I added fuel via an external fuel supply (tank will need work), it started dripping out the bottom of the carbs somewhere after a bit. I assume this is stuck floats/dirty needles not shutting off the supply of fuel so carbs are overflowing?

    Thanks for any help.

    #2
    Does it still have 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

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      #3
      Hmm, haven't checked! I'll have to pop the cover off and have a look to see whether its original points or if someone put in a Dyna-type ignition.

      Comment


        #4
        Just to be sure, you are grounding the base of the plugs against a medal surface while checking, plug wire just plugged to spark plug won't make a spark unless it's grounded.
        1983 GS1100E, 1983 CB1100F, 1991 GSX1100G, 1996 Kaw. ZL600 Eliminator, 1999 Bandit 1200S, 2005 Bandit 1200S, 2000 Kaw. ZRX 1100

        Comment


          #5
          Originally posted by 1983lux View Post
          Hey all,

          Working on Resurrecting at 79 GS1000E. After cleaning up the inside of the ignition switch and wiggling the fuses around, i managed to get the oil/neutral light to come on and the bike will turn over. However, it would not start. I removed a plug and when inserting the loose plug in each spark plug wire end, I see no spark at the gap for any of the 4 plug wires. What are some things to check?.
          Plus one on rphillips.

          And does the battery have enough voltage to run the starter AND the ignition?

          (Easy stuff first.)
          Jim, in Central New York State.

          1980 GS750E (bought used June,1983)
          1968 CB350 Super Sport (bought new Oct,1968)
          1962 CA77 305 Dream (bought used Feb,1963)

          Comment


            #6
            Check voltage at the coils (the org/wht circuit).

            More specifically:
            Check battery voltage with key off, and with key on.
            Check voltage at coils with key on.
            Check voltage at coils when cranking starter.
            Report here.

            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


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              #7
              Hey guys,

              Sorry it took me so long to check on things, haven't had much time for the bike lately.

              Popped the cover and the bike still has the original points ignition.

              I was grounding the plug, but maybe not the right way. The threads should be touching the outside of the engine block while I'm turning it over in order to see a spark I guess?

              Here's the volt readings on the battery and orange/wht wire going to one of the coils:

              Battery with key off - 12.98 volts (battery is only a few weeks old and is on tender when I'm not there)
              Battery with key on - 12.47 volts
              Org/wht coil wire with key on - 10.92 volts
              Org/wht coil wire while turning the engine over - 8.67 volts

              Do those readings look normal?

              Thanks!

              Comment


                #8
                Originally posted by 1983lux View Post
                .
                .
                .
                Org/wht coil wire with key on - 10.92 volts
                Org/wht coil wire while turning the engine over - 8.67 volts

                Do those readings look normal?
                .
                Nope.

                Too low of voltage at coils for the ignition to operate.
                If you want to conduct a test to prove it to yourself, run a temporary jumper wire from battery+ (or main, or aux) to the coils, and see if get spark then.
                Note: THis is pretty much what the "Coil relay mod" does for you, but does it only when key is on.

                The real fix is to find where are loosing the voltage, and fix that. Maybe the problem is at/in the ignition swtich, maybe in the fuse block, but probably in the wiring from the main fuse to the ignition switch, and probably some at all of the above and that all adds up to the about 2 volt drop from battery to the coils. THe additional one volt droop when cranking starter is related to strength of battery, and isnt too bad, but when already loosing two volts due to voltage drop.......

                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


                  #9
                  I'd say you are working on my 82 450a
                  I have the same issue so may jumper from the solonoid direct to the coils (orange / white) Though your voltage drop is quite a bit less than mine
                  13.08 at battery
                  Mid 10s at coils (no crank)
                  Mid 8's at coils cranking.
                  Though I don't have points.

                  Good luck on yours and let us know what you find out.

                  Alt
                  "You are replying to the most modest person you will ever know."

                  1982 Suzuki GS 450A
                  1980 Honda CM400A
                  2002 Honda Relex
                  1957 H35 Bonanza

                  Comment


                    #10
                    Sorry to revive an old thread, but finally got around to working on the bike again. Bad voltage was fixed by some good cleaning of the wiring harness. However, the real culprit was that the points plate was cracked and grounding out! An amazon electric ignition fixed the issue and bike now runs! However, time to rebuild those badly leaking carbs. Drained oil and it was mixed with a lot of fuel, glad I didn't run the bike for long!

                    Comment


                      #11
                      Be sure to check the pet cock, From what I've seen from GS's, the vacuum petcock is more often the cause of gas in oil than the carbs... Just my opinion.
                      1983 GS1100E, 1983 CB1100F, 1991 GSX1100G, 1996 Kaw. ZL600 Eliminator, 1999 Bandit 1200S, 2005 Bandit 1200S, 2000 Kaw. ZRX 1100

                      Comment


                        #12
                        Ah good to know, thanks for the tip! I noticed the gas tank on my bike is not from 1979, and someone has relocated the petcock further back on the tank. The existing one leaks, was put on with some kind of gasket goop. Amazon sells some pretty cheap replacements so I'll go ahead and get one.

                        Comment


                          #13
                          "80" GS1000's had CV carbs, their tops were much larger than the "79" VM's. Suzuki moved the petcock appx. 1 1/2 " back so it wouldn't hit the bigger carb tops. Also the "80" pet cock were totally different, I'm not sure if the bolt spacing is the same for both models or not. Surely somebody here knows for sure.
                          1983 GS1100E, 1983 CB1100F, 1991 GSX1100G, 1996 Kaw. ZL600 Eliminator, 1999 Bandit 1200S, 2005 Bandit 1200S, 2000 Kaw. ZRX 1100

                          Comment


                            #14
                            Originally posted by rphillips View Post
                            "80" GS1000's had CV carbs, their tops were much larger than the "79" VM's. Suzuki moved the petcock appx. 1 1/2 " back so it wouldn't hit the bigger carb tops. Also the "80" pet cock were totally different, I'm not sure if the bolt spacing is the same for both models or not. Surely somebody here knows for sure.
                            Iirc, the oddball petcock (with the screw-slot selector) has a hole spacing of 50mm.
                            ---- Dave
                            79 GS850N - Might be a trike soon.
                            80 GS850T Single HIF38 S.U. SH775, Tow bar, Pantera II. Gnarly workhorse & daily driver.
                            79 XS650SE - Pragmatic Ratter - goes better than a manky old twin should.
                            92 XJ900F - Fairly Stock, for now.

                            Only a dog knows why a motorcyclist sticks his head out of a car window

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                              #15


                              ​Here's a pic of what I've got going on with the tank that came with the bike. you can see the plate covering up where the petcock (originally?) went, and the one that's on it now further back.
                              Attached Files
                              Last edited by 1983lux; 09-23-2023, 03:00 PM.

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