1985 Mercury 7.5 full speed problems

Discussion in 'Outboards' started by kenrahe, Jul 23, 2011.

  1. kenrahe
    Joined: Apr 2010
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    Location: pomfret ct

    kenrahe Sunseeker

    I checked and they are there on those links hope to here from you soon maybe you can tell the year from these and you'll see no thermostat the picture of the hose is the water outlet from the head
     
    Last edited: Jul 26, 2011
  2. kenrahe
    Joined: Apr 2010
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    Location: pomfret ct

    kenrahe Sunseeker

    how do i attach a photo not using photobucket and do i have to make a new post with that title or can i change the were talking now
     
  3. kenrahe
    Joined: Apr 2010
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    Location: pomfret ct

    kenrahe Sunseeker

    just found it DSC00412.JPG

    DSC00413.JPG

    DSC00414.JPG
     
  4. kenJ
    Joined: Jul 2005
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    Location: Williamsburg, VA

    kenJ Senior Member

    re

    According to http://store.eastcoastmarineservice.com/category_s/2687.htm

    The only Lightning outboard was a 10 hp made in '47-49. So the next step is to ID what you really have. They have had serial numbers on them since the 40's, need to find the SN. Looks like the motor has been repainted, might have to do some scraping. If you have a tag it could be located on either side of the pivot housing, see pic. Most engines were stamped on top of the block above the exhaust plates, it may look like a plug. (see pic)

    Once you find it, look it up on the above site. They also have a forum, as does http://www.outboardrepairs.com/mercury/

    Once you get an ID, might want to ask your questions at one of them to get specific info, rather than the general help we can give.

    Your pictures came in while I was typing. Have you pulled the hose off to ensure there is not a thermostat hidden in there?
     

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    Last edited: Jul 26, 2011
  5. kenrahe
    Joined: Apr 2010
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    Location: pomfret ct

    kenrahe Sunseeker

    The hose connects to a small outlet tube about a 1/2 long same size as hose directly off the head i looked into the older models an can find no image that looks like mine is it possible that it's a lighting powerhead on a newer body
    DSC00412.JPG see the little tube the hose connects in the picture
     
    Last edited: Jul 26, 2011
  6. kenrahe
    Joined: Apr 2010
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    Location: pomfret ct

    kenrahe Sunseeker

    DSC00413.JPG

    DSC00423.JPG

    DSC00422.JPG

    DSC00421.JPG

    DSC00420.JPG

    DSC00424.JPG here's more pictures does this look like a 47-49 motor and can you send a farther away pic off where i should look for the plug there is no tag anywhere
     
    Last edited: Jul 26, 2011
  7. kenJ
    Joined: Jul 2005
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    Location: Williamsburg, VA

    kenJ Senior Member

    I think I would post picture 423 on one or both of the websites I listed earlier and ask for what year range for that style cover and where to look for the serial #. From the general look of it, I'm thinking 60 or 70's.

    There are also several other websites...google old merc
     
  8. kenJ
    Joined: Jul 2005
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    Location: Williamsburg, VA

    kenJ Senior Member

    Slow day at work. According to the cowl and tiller handle design I think it is an early '70s model. I emailed Oldmerc.com this is their reply:

    "The serial number should be located on the swivel bracket, either across the front just below the powerhead, or on a rearward face of this same suspension piece."

    Start scraping paint until you find it. :)
     

  9. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    If this motor is like the newer ones it won't have a thermostat installed when new even though the parts diagram shows one.

    A hot and spitting pee stream can mean a blown head gasket, this is the only way to get instant heat too. Even without a thermostat the water should be cool for a couple of minutes until the motor warms up.
     
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