Skip to content
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
Skins
  • Light
  • Cerulean
  • Cosmo
  • Flatly
  • Journal
  • Litera
  • Lumen
  • Lux
  • Materia
  • Minty
  • Morph
  • Pulse
  • Sandstone
  • Simplex
  • Sketchy
  • Spacelab
  • United
  • Yeti
  • Zephyr
  • Dark
  • Cyborg
  • Darkly
  • Quartz
  • Slate
  • Solar
  • Superhero
  • Vapor

  • Default (Slate)
  • No Skin
Collapse
Brand Logo

DT125R FORUM

  1. Home
  2. Owners Build Threads
  3. Other
  4. CB750 scrambler project

CB750 scrambler project

Scheduled Pinned Locked Moved Other
139 Posts 11 Posters 20.4k Views 2 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • S Offline
    S Offline
    SpookDog
    wrote on last edited by
    #72

    Congrats! It’s nice to see someone doing their own thing! Nearly every ride I’ve ever had has been a butchers tripe mix of a thing. Mostly through necessity though! 🙄
    I’d really love to do a street tracker out of an old Honda CB 200 twin. Nice & lite yet revvy & torquey enough. Think of Girl with the dragon tattoos bike with attitude ☠️
    They aren’t easy to find anymore though...

    Louis-DT-WRL 1 Reply Last reply
    1
    • S SpookDog

      Congrats! It’s nice to see someone doing their own thing! Nearly every ride I’ve ever had has been a butchers tripe mix of a thing. Mostly through necessity though! 🙄
      I’d really love to do a street tracker out of an old Honda CB 200 twin. Nice & lite yet revvy & torquey enough. Think of Girl with the dragon tattoos bike with attitude ☠️
      They aren’t easy to find anymore though...

      Louis-DT-WRL Offline
      Louis-DT-WRL Offline
      Louis-DT-WR
      wrote on last edited by
      #73

      @SpookDog you could do what I did and buy a frame and build it up

      1 Reply Last reply
      1
      • Louis-DT-WRL Offline
        Louis-DT-WRL Offline
        Louis-DT-WR
        wrote on last edited by
        #74

        I'm not very familiar with this bike or twin terminal coils.

        Bike won't start, I believe it's electrical problem.
        No spark.

        The CDI I bought might be the problem.

        On the coil it has 2 electrical connectors (both +) and earth's to chassis.

        Ignition on and kill switch to run the voltage on 1 terminal (yellow and blue wire) to both coils has 12v.

        But there nothing on the other 2 black / white wires. Not even when cranking over.
        Surely there should be 12v to both terminals?

        1 Reply Last reply
        0
        • CalumC Offline
          CalumC Offline
          Calum
          wrote on last edited by
          #75

          Depends where you are measuring from. The coils job is to take the 12V DC and step it up to 20KV. So you measuring at 12V is outside the scopes range.

          12V isn't enough to jump the spark plug gap.

          Measuring Coils is usually done through impedance test on the primary to secondary, secondary to spark plug cap. Should fall within the tolerances outlined by the manufacturer.

          Always Originate, Never Pirate!

          Louis-DT-WRL 1 Reply Last reply
          0
          • Louis-DT-WRL Offline
            Louis-DT-WRL Offline
            Louis-DT-WR
            wrote on last edited by
            #76
            This post is deleted!
            1 Reply Last reply
            0
            • Louis-DT-WRL Offline
              Louis-DT-WRL Offline
              Louis-DT-WR
              wrote on last edited by
              #77

              Its a wasted spark system btw

              1 Reply Last reply
              0
              • CalumC Calum

                Depends where you are measuring from. The coils job is to take the 12V DC and step it up to 20KV. So you measuring at 12V is outside the scopes range.

                12V isn't enough to jump the spark plug gap.

                Measuring Coils is usually done through impedance test on the primary to secondary, secondary to spark plug cap. Should fall within the tolerances outlined by the manufacturer.

                Louis-DT-WRL Offline
                Louis-DT-WRL Offline
                Louis-DT-WR
                wrote on last edited by
                #78

                @Calum thanks, I'm pretty sure both coils are bad. No resistance at all between power/trigger and the caps.

                They were second hand, came with the loom.

                12.8 volts on the looks power connectors.

                New coils, leads and caps on order 🤞

                I

                1 Reply Last reply
                0
                • S Offline
                  S Offline
                  SpookDog
                  wrote on last edited by
                  #79

                  Wasted spark is when they both spark at top dead centre?
                  Have you not gotten any old coil off of another bike? Even a single one that you can get to spark? It would at least prove the rest of the circuit was on par...

                  Louis-DT-WRL 1 Reply Last reply
                  1
                  • S SpookDog

                    Wasted spark is when they both spark at top dead centre?
                    Have you not gotten any old coil off of another bike? Even a single one that you can get to spark? It would at least prove the rest of the circuit was on par...

                    Louis-DT-WRL Offline
                    Louis-DT-WRL Offline
                    Louis-DT-WR
                    wrote on last edited by
                    #80

                    @SpookDog yes wasted spark system is that.

                    I've ordered new coils as the primary has 3 ohms which is fine but secondary resistance has no resistance at all. On both. This is 1 fault. I'll have to see if there is others.
                    They are very old and probably corroded inside

                    1 Reply Last reply
                    0
                    • Louis-DT-WRL Offline
                      Louis-DT-WRL Offline
                      Louis-DT-WR
                      wrote on last edited by
                      #81

                      This is the confusion I have , electrics are not my strongest point.

                      The manual says the yellow/blue wire goes at the top connector on both coils...

                      alt text
                      alt text

                      The coils are not handed so the green terminal is at the top on one side and black at the bottom when installed.

                      alt text

                      alt text

                      That's a what's confusing me 🤔
                      I'm still waiting for the new plug caps to try.

                      I'm also not sure if I need to loop the sidestand indicator light as I removed it... I'm pretty sure it just piggybacks

                      1 Reply Last reply
                      0
                      • S Offline
                        S Offline
                        SpookDog
                        wrote on last edited by
                        #82

                        If it’s connected to the ignition it could be the cause of your problem, specially if you’re neutral lights not working...

                        Louis-DT-WRL 1 Reply Last reply
                        1
                        • S SpookDog

                          If it’s connected to the ignition it could be the cause of your problem, specially if you’re neutral lights not working...

                          Louis-DT-WRL Offline
                          Louis-DT-WRL Offline
                          Louis-DT-WR
                          wrote on last edited by
                          #83

                          @SpookDog alt text

                          Do you think that's the problem looking at this?

                          To me it looks like if the neutral light is on (which it is) it should start.

                          1 Reply Last reply
                          0
                          • CalumC Offline
                            CalumC Offline
                            Calum
                            wrote on last edited by
                            #84

                            So it looks like according to the diagram that the G/W wire needs to be tied to Earth if you want to bypass the side stand switch. The Y/Bl wire can just be taped up. I.E. don't complete the circuit for that.

                            Always Originate, Never Pirate!

                            Louis-DT-WRL 1 Reply Last reply
                            0
                            • CalumC Calum

                              So it looks like according to the diagram that the G/W wire needs to be tied to Earth if you want to bypass the side stand switch. The Y/Bl wire can just be taped up. I.E. don't complete the circuit for that.

                              Louis-DT-WRL Offline
                              Louis-DT-WRL Offline
                              Louis-DT-WR
                              wrote on last edited by
                              #85

                              @Calum I have the sidestand switch, all plugged in. Only the indicator light isn't connected. Does that affect it? Cheers.

                              Also still confused on the wires to the green or black connectors on the coils.

                              1 Reply Last reply
                              0
                              • CalumC Offline
                                CalumC Offline
                                Calum
                                wrote on last edited by
                                #86

                                The light only needs to be there if the side stand is down by the looks of it.

                                Always Originate, Never Pirate!

                                Louis-DT-WRL 1 Reply Last reply
                                0
                                • CalumC Calum

                                  The light only needs to be there if the side stand is down by the looks of it.

                                  Louis-DT-WRL Offline
                                  Louis-DT-WRL Offline
                                  Louis-DT-WR
                                  wrote on last edited by
                                  #87

                                  @Calum that's what I'm thinking but if in neutral then it shouldn't Matter ,?

                                  1 Reply Last reply
                                  0
                                  • S Offline
                                    S Offline
                                    SpookDog
                                    wrote on last edited by
                                    #88

                                    I can’t get my head round the diagram at the mo. There are a lot of differences from what I know. What about the diode (number 7) condition?
                                    I know that the live wires on the coils will only affect spark timing if wrong, they should still spark. So I’m guessing that the problem is with the side stand, neutral, cutout circuit somewhere, if there’s no spark still...
                                    Sorry I can’t be more help at the mo’. Too many brewskies!🤪

                                    Louis-DT-WRL 2 Replies Last reply
                                    0
                                    • S SpookDog

                                      I can’t get my head round the diagram at the mo. There are a lot of differences from what I know. What about the diode (number 7) condition?
                                      I know that the live wires on the coils will only affect spark timing if wrong, they should still spark. So I’m guessing that the problem is with the side stand, neutral, cutout circuit somewhere, if there’s no spark still...
                                      Sorry I can’t be more help at the mo’. Too many brewskies!🤪

                                      Louis-DT-WRL Offline
                                      Louis-DT-WRL Offline
                                      Louis-DT-WR
                                      wrote on last edited by
                                      #89

                                      @SpookDog yes it's a crappy diagram, I assume the second bulb is the neutral one.

                                      I've never had a diode go wrong on anything but might test it.
                                      I think it's the side stand ... I'll do more tests when the plug caps come.

                                      Thanks

                                      1 Reply Last reply
                                      0
                                      • S SpookDog

                                        I can’t get my head round the diagram at the mo. There are a lot of differences from what I know. What about the diode (number 7) condition?
                                        I know that the live wires on the coils will only affect spark timing if wrong, they should still spark. So I’m guessing that the problem is with the side stand, neutral, cutout circuit somewhere, if there’s no spark still...
                                        Sorry I can’t be more help at the mo’. Too many brewskies!🤪

                                        Louis-DT-WRL Offline
                                        Louis-DT-WRL Offline
                                        Louis-DT-WR
                                        wrote on last edited by
                                        #90

                                        @SpookDog I think if I try to crank the engine over (on the starter motor) in gear but with the clutch switch pulled in... That would also prove if the silicon diode is faulty 🤔

                                        1 Reply Last reply
                                        0
                                        • S Offline
                                          S Offline
                                          SpookDog
                                          wrote on last edited by
                                          #91

                                          A diode only lets electric pass one way I think. I’d try a continuity/bulb test

                                          1 Reply Last reply
                                          0
                                          Reply
                                          • Reply as topic
                                          Log in to reply
                                          • Oldest to Newest
                                          • Newest to Oldest
                                          • Most Votes


                                          • Login

                                          • Don't have an account? Register

                                          • Login or register to search.
                                          • First post
                                            Last post
                                          0
                                          • Recent
                                          • Tags
                                          • Popular
                                          • Users
                                          • Groups