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  1. #1

    Default Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    I just recently purchased the boat and have been trying to get it started for a week or two now. I havenít been able to get it to start once. The guy I got the 86 Forester 164 Phantom from said the outboard is a 87 Mercury 115 2 stroke.

  2. #2
    Join Date
    May 2007
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    Ireland,the only country in the world you can go North to go South
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    I would start with a spark ,fuel and compression tests.Post number of the outboard as well.

  3. #3
    Join Date
    Sep 2010
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Are you pushing the key in WHILE cranking it over , yes or no ?

  4. #4

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    I am pushing the key in while trying to crank it over. I seen looking online that is how the choke works. I’ve also trying lifting up the fast throttle lever.
    To haventaclue: what do you mean by posting a picture of the outboard number? Where is the number located?

  5. #5
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    The number is on a plate on the bracket Bxxxxxx if it's '87.Just in case there are any problem specif to that particular Merc.
    But back to basics,spark,fuel and compression,'cause if you are missing one of those,she ain't going to start.

  6. #6
    Join Date
    May 2013
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    TX.
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Fresh fuel and a fully charged, in good working order battery are necessary prior to attempting to start. If in doubt verify before attempting.

    Starting procedure is normally: Engine vertical works best for me on initial starts, not tilted way up or way down. Fast idle lever all the way up, gear shift/throttle lever in Neutral, squeeze the primer bulb located in the fuel line to the engine till the bulb gets hard.....resists further squeezing. Turn the ignition key to the first position: ON.

    If a separate primer button is supplied push in and hold for 5-30 seconds depending on how long it's been since the engine has been operated...longer, the longer. If key push type primer, push in on the key and hold for that interval.

    Roll the key over to START while still holding the button/key depressed and allow the engine to crank for 15 seconds. If no response, squeeze the bulb again till firm and repeat the process several times as required. If it doesn't light off you have a problem to explore.

    Once it lights off, reduce the fast idle lever such that you are controlling the RPMs at about 1500. If the engine stumbles, push in the primer button/key till it recovers and release....repeat as necessary till it warms up sufficiently to run on it's own. Put the fast idle lever all the way down and be on your way.

  7. #7
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    A motor in good condition start right up on first attempt.----Prime bulb.----Raise fast idle lever.----Push key in and hold it in while cranking it over.

  8. #8
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Quote Originally Posted by racerone View Post
    A motor in good condition start right up on first attempt.----Prime bulb.----Raise fast idle lever.----Push key in and hold it in while cranking it over.
    My engines are in good condition and if I used them the previous day, what you say is fact. If I only use them every other month, what you say isn't.....with my equipment!

  9. #9

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Thank you to you all that responded with info and advice. I finally got my motor to start up today and it seems to be running pretty good.
    I do have a couple questions about it though. There is what seems to be a barbed hose fitting in the center of the head or exhaust manifold right in between the 3rd and 4th spark plugs. It doesn’t have a hose connected to it. It’s just open and while the engine runs it’s just shooting water out of it. Is this how it’s suppose to be? Is there suppose to be a cap or something there? Or is there suppose to be a hose hooked up to it? If there is a hose suppose to be going to it where is the hose suppose to go to?
    Also there is a small hose sticking out of the lower unit or by the lower unit. Maybe it’s somehow suppose to to run all the way up and connect to the fitting in between the spark plugs? It doesn’t seem like it runs bad or anything because of either of these two things. I kind of feel like with the engine cover on the water shooting out from the fitting by the spark plugs will just fill up the whole inside of the engine cover. So I really feel as though something needs to be connected to it or a cap or something needs to be there instead of the hose fitting.
    I am going to try to attach pictures of the two things
    I cannot figure out how to attach any pictures

  10. #10
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    The small hose from lower unit is to provide a signal for a speedometer at the helm.

  11. #11
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    The fitting in the middle of the block,pumping water, is for a water pressure gauge

  12. #12
    Join Date
    May 2020
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    Stokesdale NC
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Does your boat have a water pressure gauge on the dash? If so that is likely where the water fitting by the plugs is going to go.

  13. #13

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Is there suppose to be a plug screwed into the hole instead of the hose fitting or is there suppose to be a rubber cap on the fitting? Should I just take out the fitting and find a bolt that will fit in the hole?

  14. #14
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    If there is no gauge then put a pipe plug of the correct size in the hole.

  15. #15

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    I’m pretty sure there isn’t a water gauge. I think there’s just a fuel, volts, and speedometer.
    I should be able to get a pipe plug for it from any auto parts store?

  16. #16
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    That or a hardware store.

  17. #17

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    And then with the small hose coming from the lower should I plug it somehow? It just looks like a small diameter vacuum hose with a barbed plastic adapter in it.

  18. #18
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Yes plug it to keep out crap. If oil inj. lines are original, carefully replace them all, or you may do what I did and burn up the motor some dark night out on the water.
    Last edited by timguy; 07-21-2020 at 12:46 PM. Reason: Typo

  19. #19
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    If the hose fitting you are talking about is on the right side towards the back of the engine as your looking forward then there should be another at the top of the block. They are air vents for the cooling system, don't plug them they should be connected together top to bottom.

  20. #20
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    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    Oops, just reread the earlier post, the hose coming up from the front of the lower unit is a speedometer pick up just like the pitot tube that's commonly mounted on the back of the boat, it's just built in to the lu.

  21. #21

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    You won't believe this one. Two mechanics but I am not familiar with boats. My friend had a 1990 Fisher 18GT (Grey Thunder) with Mercury 2 stroke 115 hp motor. We have gone to my lake place with his boat and he tried to start it. No go! He said that he knew that it had plenty of fuel. Good spark, pushed in the choke, etc. He took the motor covers off and there was gas leaking from the carburetor. We checked wiring everything that we could. Then he had an epiphany. He said that he had washed his boat and somehow had turned off the kill switch underneath the ignition switch. He flipped it back on and it started right up. The carburetor was flooded. Never forget the basics. Lesson learned.

  22. #22

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    What was causing your no start condition?

  23. #23

    Default Re: Is anyone familiar with a 1987 Mercury 115hp 2 stroke???

    I remember seeing what looked like a small vacuum hose which was cut in two while we inspected the motor. Maybe that is what it is for the speedometer.Thanks.

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