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  1. #1
    Sly Fox DKFox's Avatar
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    Angry Weak Spark has developed with MSD ignition enhancer... need an expert.

    1998 SeaDoo SPX (787 engine). I’ve been fighting problems with this ski ever since I bought it a year ago! I’ve rebuilt the top end, done all the fuel line conversions, new wear ring, and rebuilt the carbs all trying to get this thing to move faster than idle speed in the water. Put it into the river this past weekend and a smile came to my face… because it took off! However, I never went above ½ throttle since I’m still breaking in the engine. After 3 minutes of riding it just quit and it didn’t want to start back up. Last night I checked for spark and it is REALLY weak. Here is my question:
    This thing is a former race ski. It has an MSD ignition enhancer. Using the dip switches there is no way to increase the amount of spark, right? All you can do is set variable timing of the spark and place a new rev limit, right? Then what is the most likely cause for weak spark? Guess it would be either the pickup, coil itself, or MPEM? (Not the spark plug itself because I checked spark to ground.)
    I don’t have the original MPEM, so I can’t easily go back to it. I might try to find a web reference to see if the MPEM out of my 1995 XP or 1996 SPI will work in this ski. If the spark is still weak then at least I could rule out the enhancer.

    Ideas are welcomed. P.S. Forgot to mention:

    1.) The battery is definitely good. Odyssey gel cell that works fine when placed in my other skis too.
    2.) Yes, I've trimmed back the plug wires.
    3.) This ski does not have a DESS so the pole is not the problem.


  2. #2
    Sly Fox DKFox's Avatar
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    Feb 2009
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    I may have read and found my own problem! Bad ground. Per the service manual attachment the photo shows a small ground wire on the battery lug. I know for a fact mine does not have that. I need to check for that and any other engine ground connection. Maybe I was digging too deep before.... sure hope so.
    Click image for larger version. 

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