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  1. #1
    Member
    Join Date
    Sep 2014
    Location
    Kokomo IN
    Posts
    24

    Mariner Magnum II 150/Mercury XR4 2.4L has spark but only fires once - doesn't start

    I have the engine in the title (Mariner version) that won't start. Originally it had no spark and I traced that down to the CDI switch modules (both had no spark). Verified trigger was good with an oscilloscope and stator was good. Just got new CDI modules and not I have spark. Now the problem is I only get 1 combustion event and that firing event seems to stop the engine dead (starter drive gear drops out of the flywheel) as if the spark is firing at the wrong time?

    I'm pretty sure the trigger wheel is set correctly because when I move the throttle to WOT the trigger wheel moves counter clockwise (advancing timing) like I think it should and I'm pretty sure I have the wires on correctly (yellow bundle on the front CDI module).

    I should also note that I'm getting this one combustion event on starter fluid. The engine hasn't run in about 6 years (although it did run when parked) so I was surprised that the CDI modules would go bad just sitting there. I'm not surprised that it won't run on the old gas or I may have carb issues which is why I'm wanting to see if it will run a bit on starter fluid before I tackle fuel problems. But I'm expecting it to fire more than just once on that starter fluid - this one fire which seems to kick the engine backwards can't be right - there's got to be something I've put back together wrong - any ideas?

    (Full disclosure - I posted this in marineengine.com forums too)

  2. Member
    Join Date
    Sep 2014
    Location
    Kokomo IN
    Posts
    24
    #2
    Just to close this thread in case anyone was wondering, I found upon closer inspection with a brighter light that I had 2 wires crossed from the stator to inside CDI switch module. The white and brown were crossed. Apparently the white is dirty enough with age in the dim light it looked brown and the brown faded enough it looked white. Fixed that and I have correct spark timing and motor will fire and run on starter fluid, but not off the carbs so still troubleshooting that! I may have another post with a fuel question! But spark looks good now!

  3. Member
    Join Date
    Jun 2013
    Location
    LONGVIEW TEXAS
    Posts
    13,938
    #3
    easy mistake to make,please don't use starting fluid,has no oil in it
    .................................................. ...the scariest thing in life is the unknown ...................................