# BOAT WON'T START AFTER RUNNING



## bill hockensmith (Feb 8, 2019)

I HAVE A MERCURY 90 HP OUTBOARD 4 STROKE. IT STARTS GOOD COLD, RUNS GOOD. IF I STOP AFTER AWHILE IT WILL SHUT OFF WHEN GOING SLOW AND WON'T START UP.
IT WILL START UP AGAIN AFTER ABOUT 5 MINUTES.


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## Smackdaddy53 (Dec 31, 2012)

Why are you yelling?


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## EdK13 (Oct 3, 2013)

Smackdaddy53 said:


> Why are you yelling?


I can recall "someone" you know having similar reactions when he had one of those motors.


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## SomaliPirate (Feb 5, 2016)

EdK13 said:


> I can recall "someone" you know having similar reactions when he had one of those motors.


Ha!


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## bill hockensmith (Feb 8, 2019)

Smackdaddy53 said:


> Why are you yelling?


I DON'T UNDERSTAND, I'M NOT YELLING


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## nautilott (Oct 29, 2017)

All upper case(caps) = yelling


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## bill hockensmith (Feb 8, 2019)

nautilott said:


> All upper case(caps) = yelling


ok, can any one help with my problem?


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## nautilott (Oct 29, 2017)

Hey, Bill...Welcome to the site. Someone will be along directly to help you out.


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## Guest (Feb 8, 2019)

AT A GLANCE, IT SOUNDS LIKE A HEAT SOAK ISSUE! THIS CAN HAPPEN ON FOUR STROKES TOO! IS THIS A NEW MOTOR FOR YOU?


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## BassFlats (Nov 26, 2018)

THANKS FOR YELLING JAMES. I'M HARD OF HEARING.


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## Brett (Jul 16, 2008)

I had a 140 with a brainbox issue.
Cold it would start up no problem.
Hot it'd crank but not spark.
Tap the brainbox with the butt end of a screwdriver
it'd wake up and fire on the first crank.
Lived with the problem until I could afford a new controller.
Pop the cowling, rap the brainbox, start the outboard,
put the cowling back on and head to the next spot.
Lived with it for almost 6 months.
Not a cheap part.


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## bill hockensmith (Feb 8, 2019)

Boatbrains said:


> AT A GLANCE, IT SOUNDS LIKE A HEAT SOAK ISSUE! THIS CAN HAPPEN ON FOUR STROKES TOO! IS THIS A NEW MOTOR FOR YOU?


what's a "heat soak" problem I just got this boat a month ago. My last one was a smaller Yamaha, never had a problem. It was a 2 stroke


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## bill hockensmith (Feb 8, 2019)

Brett said:


> I had a 140 with a brainbox issue.
> Cold it would start up no problem.
> Hot it'd crank but not spark.
> Tap the brainbox with the butt end of a screwdriver
> ...


 thanks for the help, i'm not real good with the motor, where is the "brain box" ?


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## topnative2 (Feb 22, 2009)

should be a black square box mounted on the head...side or rear


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## Brett (Jul 16, 2008)

Also known as the CDI unit
Check the Merc parts diagram for your outboard.
YouTube has some vids for checking the electrical system for function.


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## bill hockensmith (Feb 8, 2019)

topnative2 said:


> should be a black square box mounted on the head...side or rear


thanks, i'll try it tomorrow


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## topnative2 (Feb 22, 2009)

bill hockensmith said:


> thanks, i'll try it tomorrow


google a diagram


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## bill hockensmith (Feb 8, 2019)

someone said heat soaked. what is that? I also read it could be the distributor cap and rotor. Any thoughts?


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## Guest (Feb 9, 2019)

Ha, I said heat soak... pretty sure it’s not the cap and rotor
Heat soak is basically where the fuel is boiled out of carb bowl or the vst tank. @Brett ‘s suggestion about the cdi/power pack/switch box is also a pretty solid area to be inspecting. Easy way to check for heat soak...
After shutting down, before you try to start just pump the primer until it is firm. Turn key on, wait 2-3 seconds and try to start. If it starts right up the it is probably a heat soak issue. If it still fails to fire right up then it is not.


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## bill hockensmith (Feb 8, 2019)

Boatbrains said:


> Ha, I said heat soak... pretty sure it’s not the cap and rotor
> Heat soak is basically where the fuel is boiled out of carb bowl or the vst tank. @Brett ‘s suggestion about the cdi/power pack/switch box is also a pretty solid area to be inspecting. Easy way to check for heat soak...
> After shutting down, before you try to start just pump the primer until it is firm. Turn key on, wait 2-3 seconds and try to start. If it starts right up the it is probably a heat soak issue. If it still fails to fire right up then it is not.


all right , thanks i'll give it a try


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## bill hockensmith (Feb 8, 2019)

now another problem I can sure use some help with.
my motor is making oil. I've been told the gas is mixing with the oil. I've run it maybe 5 hours since oil change and it now has more oil than it started with. the mechanic didn't know what I was talking about and didn't know how to fix it. I just checked it , it is over full and has a gas smell to it. any ideas?


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## Guest (Feb 9, 2019)

bill hockensmith said:


> now another problem I can sure use some help with.
> my motor is making oil. I've been told the gas is mixing with the oil. I've run it maybe 5 hours since oil change and it now has more oil than it started with. the mechanic didn't know what I was talking about and didn't know how to fix it. I just checked it , it is over full and has a gas smell to it. any ideas?


What fuel lift pump does it have? If it’s a cam driven diaphram pump thenit could be leaking into the crank case. Otherwise probably improper break in resulting in washed rings that never seated! Do a shock treat with yamaha ring free and run the hell out of it then change oil and spark plugs! By run the hell out of it, I meen allow to warm up and then WFO for as long as you can. Is it reaching maximum rpms?


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## bill hockensmith (Feb 8, 2019)

Boatbrains said:


> What fuel lift pump does it have? If it’s a cam driven diaphram pump the it culd be leaking into the crank case. Otherwise probably improper break in resulting in washes rings that never seated! Do a shock treat with yamaha ring free and run the hell out of it then change oil and spark plugs! By run the hell out of it, I meen allow to warm up and the WFO for as long as you can. Is it reaching maximum rpms?


i'm not sure on the pump, but i'll try the ring free and run the hell out of it. lol


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