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  • Misfire

    1984 115 ETLN

    Takes a long time to warm up then runs great for the rest of the day. Feels like one of the cylinders is misfireing. No obvious clues to which cylinder from plug inspection.

    Found that when running from cold start in my driveway there was no spark from one of the coils plull the cap w/insulated pliers and hold close to plug to see the spark jump). Replaced the coil, still no spark. Pulled all coils one at a time and cleaned/filed grounding surfaces and leads to each cylinder. New coil and old now spark/fire in the original position. Now another one of the coils won't spark. Swapped out with the new coil and still no spark.

    CDI? Any clues?

    Thanks......

  • #2
    It could be any of the ignition, charge coil, pulsor coil , CDI or wiring. Parts replacement gets expensive, need to have ignition system tested.
    Regards
    Boats.net
    Yamaha Outboard Parts

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    • #3
      I checked the values listed in the shop manual. Charge and Pulser (trigger?) coil readings are within the +- range listed.

      When attemting to read the CDI values to each coil I get nothing close to what the manual lists - brown and red to black/white = 90~ cold and drops to 42~ when hot (the manual lists 120~ to 180~). Blue and black/red to black/white = .529 cold and raises to .646 hot. Since I'm using a DVM and these values are whack compared to what the manual lists I intend to find an analog VM to check these again.

      Having said this, I found that in driveway testing I can get the coil to start fireing pretty quickly by applying hot air (heat gun), directly to the CDI with the terminal area exposed.

      I know I'm rambling somewhat at this point but I'm trying real hard to be right before shelling out the big bucks for a CDI.

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      • #4
        u need a dva to test ignition circuits

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