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Thread: gremlin in the wiring

  1. #1
    DRAGRACER1 Guest

    Default gremlin in the wiring

    I'm Using a MC-4 on my 04busa dragbike. I have a NOS controller that I break the 12v trigger signal over a relay that breaks over my clutch wires, (this is so the NOS wont trigger while Im on the line with the clutch pulled in and the rpms are against the 2 step). While testing I noticed that I get a shift kill like miss when I let the clutch out and it drops the relay(s), when I disconnect the relay(s) the miss goes away. All my wiring is correct and at this point the retard wires are not connected yet, (they are terminated on a dead terminal strip). The burnout wire is broken over my front brake lever, and the launch wire is broken over my clutch release button, (MPS air clutch). I cannot see a runnaround in the circiutry to cause this, unless the MC-4 feels the short of the relay coils ...2 relays ...low draw. any help is greatly appreciated. I had MSD products on 2 trucks, 2 street rods, 3 racecars and 2 bikes:001_smile: . Other than this small problem :cursing: the bike runs strong and the plugs are clean for a carb bike. thanks dragracer1

  2. #2

    Default relay

    More likely than not the problem is with your relays. Depending on the type and quality of the relays there may be some vibration resonating through the relays once the bike is launched. This would cause the problems you are describing. Would it be possible to run the relays opposite of the way you currently have them set up? Meaning that while you are staged at the line the relays are open and then engaged once the clutch is released. If this could be accomplished then vibration would have no affect on the relays once the clutch is released because the circuit is already closed. My only other suggestion would be to try to isolate the relays in some way, if this is even possible. Please let me know if you have any other questions. Thanks, Bret- MSD Powersports

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