Rough Running Merc

Discussion in 'Outboard Maintenance' started by Un-shore, Feb 18, 2010.

  1. Un-shore

    Un-shore Well-Known Member

    FYI, Started up my Merc 9.9 after sitting for a couple months to find it running rough. I could here snapping sounds around the coils. Discovered several small cracks in the coils that were leaking voltage.

    The cold wheather maybe, it is an old motor. :'(
  2. Frank_Sebastian

    Frank_Sebastian Well-Known Member

    There is a product called "Soft Seal" that will help. The company that made it was bought by CRC. If you can find it it will say CRC something and "Formerly Soft Seal" on the spray can. It really works on cracked coils. Eventually the coils will need replacing, but I have run V4 Johnsons for years with an occasional spray of it.

    I kept it on my boat all the time and when one of my friends would go out in the fall and shut down long enough for dew to form on his engine wiring, he couldn't get it to start. I would hear him on the radio looking for me and I would go over and spray the engine coils and wiring and it would fire right up. Done that at least a dozen times.

    Best regards,

  3. Un-shore

    Un-shore Well-Known Member

    Thanks Frank! I was just going to replace them but I will try that first.
  4. Brett

    Brett > PRO STAFF <

    You're a braver soul than I am... ;)

    The electrical early warning alarm has gone off.
    Run your outboard at night on the hose and watch
    the light show as the coils arc to whatever ground is nearest.
    I'd rather replace before it adheres to Murphy's Law.
    You know...worst time...worst place!