No spark

Discussion in '1st & 2nd Generation 1983-1989' started by AledoBill, Apr 27, 2019.

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  1. AledoBill

    AledoBill New Member

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    Hi All!

    I'm Bill from western Illinois and I just picked up an 86 700 interceptor that has been sitting outside under a cover for 21 years. Just bought a new battery. It turns over but there is no spark to any of the plugs. What are the most common reasons for this? I have bypassed the clutch switch and I have the kickstand up. I have Clymers manual but its not very useful.

    TIA

    Bill
     
  2. bk94si

    bk94si Insider

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    Kill switch set to run?
     
  3. AledoBill

    AledoBill New Member

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    Yes and all fuses are good. At least the fuses next to the ignition keys. Any other ones hidden throughout the bike? I have already restored a 78 CB750 but this is a whole new ball game.
     
  4. Thumbs

    Thumbs Member

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  5. squirrelman#1

    squirrelman#1 New Member

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    good idea to test compression b4 spending time or money, see what you have to work with.
     
  6. AledoBill

    AledoBill New Member

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    Good point. That would be a bummer. The compression is good. I just need to figure out how to figure out where the system is breaking down. I bypassed the clutch switch and there is no stand switch.
     
  7. squirrelman#1

    squirrelman#1 New Member

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    check at the cdi box plug to see if it's getting power. (key and run switch ON )
     
  8. AledoBill

    AledoBill New Member

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    That's a good idea. I imagine all the safety switches occur before that point. Do you know which wires bring power to the CDI off hand? Otherwise I can find a wiring diagram and figure it out. Thanks for the idea!
     
  9. AledoBill

    AledoBill New Member

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    I figured it out. It was a bad kill switch. I took the little screw inside the assembly and little pieces fell out all over. Thanks for the help!
     
  10. squirrelman#1

    squirrelman#1 New Member

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    so it's running now ?
     
  11. AledoBill

    AledoBill New Member

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    No. This is going to be a long term project. I had to drill the gas cap to get it open and it's a mess inside. I cleaned the carbs already but it still won't fire up with starter fluid. The spark looks weak. I think I'm going to clean all the connections and try again. I may replace all the carb jets as well. I'm glad I have my cb750 to ride while I work on this one.
     
  12. squirrelman#1

    squirrelman#1 New Member

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    drain and flush the fuel tank or bottle-feed the carbs at first. weak spark? try a jumper battery or make sure you have 12.6 volts on yours.
     
  13. Terry Smith

    Terry Smith Member

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    Weak sparks may likely be a result of general corrosion in terminals. I'd suggest you disconnect them all and clean then apply some dielectric grease. I had a similar problem on my ST1100 and the root cause was corrosion within the red connector which feeds power to/from the right switch pod. This manifested as low voltage at the ECU. Good luck.
     
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