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  1. #1
    Join Date
    Aug 2010
    Location
    Upstate NY, North of the Catskills, South of the Adirondacks and just East of Cooperstown....
    Posts
    29

    Default 1988 Mariner 40 hp - does it have a thermostat?

    I've noticed that the 'pee stream' starts flowing within a few seconds after the engine is started. Does this engine have a thermostat and if so, where would it be located. I'm thinking if it DOES have a thermostat, it's stuck open or the previous owner may have removed it for some reason. I've poured over the SELOC Repair Manual and can't seem to find one shown.?? The engine runs fine as it is, idles a little rough at 800-1000 rpm, runs well, starts easily -- really can't ask for more.

    Engine stats (compliments from "Haventaclue" from my 8-25-10 response to my 'what year is this' thread).

    1988 Mariner (Yamaha build) 40 Hp ELO
    SN: 6E9 430989

    Thanks for your time.....

    f.
    Just a regular guy...!

  2. #2
    Join Date
    May 2007
    Location
    Inverary, Ontario, Canada - The Great White North Eh!
    Posts
    8,505

    Default Re: 1988 Mariner 40 hp - does it have a thermostat?

    Thermostat is located under the cover directly above the top sparkplug (cover kinda looks like a figure 8 on it's side). There is also a poppet valve under that cover (a kinda poppet - not like on modern Merc's - looks more like the thermostat in your car - called a pressure relief valve back in the late 80's).

    On this particular model the tell-tale is getting it's feed from the exhaust plate (where the water first enters the powerhead), so it's "normal" for it to start flowing as soon as water makes it to the powerhead (the water channel in the exhaust plate feeds the channels in the powerhead itself).

    On the downside of this particular design, while it tells you the water pump is working fine it doesn't tell you if the water is getting past the thermostat or circulating properly through the powerhead.
    Graham

    A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)

  3. #3
    Join Date
    Aug 2010
    Location
    Upstate NY, North of the Catskills, South of the Adirondacks and just East of Cooperstown....
    Posts
    29

    Default Re: 1988 Mariner 40 hp - does it have a thermostat?

    Mr. Graham,
    Thanks for the reply... it makes sense. I've had no problem with overheating but was worried that it may be running too cool. The only way to know it there is a thermostat actually where it's supposed to be is to open her up and check. If there isn't one .... well, I'll put one in. If there IS one I'll put it into hot water to see if it's working properly. I'll be able to get to it this weekend and I'll report my findings back. Thanks again.

    f.
    Just a regular guy...!

  4. #4
    Join Date
    Aug 2010
    Location
    Upstate NY, North of the Catskills, South of the Adirondacks and just East of Cooperstown....
    Posts
    29

    Default Re: 1988 Mariner 40 hp - does it have a thermostat?

    Just pulled the thermostat and put it in a pot of water on the stove.... it opened at around 140+/- deg F. Guess all is working the way it's supposed to. That's a 'thought' that's off my mind now. Thanks Graham.

    f.
    Just a regular guy...!

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