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  1. #1

    787 XP no spark... Need help

    Hey guys, I need some help trouble shooting my no spark issue on my 787 XP.

    Here is the history:

    Just installed a brand new battery. I was having intermittent DESS post not recognized problems. I cleaned the negative cable from the battery to the starter. This cleaning fixed my intermittent DESS post not recognized problems.

    I then started the ski and it ran fine. shut it down and ran it again... all was good.

    The next day (today) I decided that I was going to go through every connector that I would get my hands on and clean them out with liquid electrical cleaner spray and then put new di-electric grease in all the connectors. I unhooked the battery and proceeded to clean all the connectors I could find. I hooked the battery back up and tried to start the ski....

    The current situation:

    I plug in the DESS key and I get the 2 beeps, gauges power up etc. (just like normal start up)....

    hit the starter button and it turns over perfectly fine... would probably crank until the starter died....

    I am getting fuel spark plugs are wet upon removal...

    compression is good....

    So that leaves me with spark.... I checked for spark and there is nothing on both plugs. I checked all of my connections to make sure they are all tight. (unplugged and replugged every connection) still no spark....

    the only things that I have that are questionable are:

    1: on the coil where the female spade connectors hook up, does the white wire go to the + side on the coil or the - side of the coil?

    2: the PO left out a couple fuses.... I would like to replace these fuses so that I know the electrical system is complete.... starting from the bottom fuse slot, what is the order of amp ratings? from bottom to top is it 15A, 5A, 7.5A?

    Other than those two things, Where should I start? I have a lot of experience in automotive and motorcycle mechanics. but jet skis are new to me....

    I checked the coil ohms from the + side to the - side spade connections and it looks to be 5 ohms... from the seadoo shop manual and the clymer manual that I have, this seems to be fine. but then again I could be testing the coil improperly...

    So help me out guys... I am somewhat lost on where to go from here....

  2. #2
    maxadrenaline's Avatar
    Join Date
    Nov 2007
    Theodore, Alabama (Home) Shelbyville, KY (Work)

    gray box

    Did you check the fuses in the gray box in the bow ?

  3. #3
    you mean the fuses in the MPEM?

    I have checked the fuses in the MPEM except for the two that are missing....
    I also checked the fuse in the black box... I believe this fuse is for the starter solenoid... other than those main fuses attached to the MPEM, I am not sure which fuses you are talking about...

  4. #4
    bump for a response....

  5. #5
    96XPSS's Avatar
    Join Date
    Feb 2006
    Warner Robins, GA Home of the 2007 All-Star Little League World Champions!
    If you had spark before moving and cleaning wires, you interrupted a ground in the process. The small black wire from the black box is normally the culprit. Unplug on the top of the box too and inspect the pins for corrosion. Run a separate temporary groung from the post in the black box to battery to confirm small ground is good or bad. Inspect the ground post in the bottom of the black box for corrosion. On the coil, white is positive, and black goes to the ground post.

    I don't know the values in order, but they are 15, 5 & 5 on the MPEM. 15 and 7.5 in the black box.

    Make sure you remove the heat shrink tubing over the crimp connector ends on the ground wire from the battery to engine. It corrodes under there, and has caused many a headache troubleshooting an electrical problem.

  6. #6
    Problem solved.... I verified that the ground to engine block was complete with my DMM... i then tried to verify signal coming through the white wire... no dice. I traced the wire back to the MPEM and opened the connector that goes into the MPEM...

    Turns out the clip inside the connector has some how become fubared... It allowed the white wire pin to back out of the large connector. this obviously kept the coil from getting its signal to fire.

  7. #7
    96XPSS's Avatar
    Join Date
    Feb 2006
    Warner Robins, GA Home of the 2007 All-Star Little League World Champions!
    Good job!

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