Cant keep the motor on 97-99 Merc 50 2 stroke

[jdmjunkiemonkie]

i purchased this boat last year with the motor on it. the person who i bought it from didnt start the motor or attempt too since it was his project from when he got it.

so when i got it home i tried to start it and it would start but wont stay on. so we i went to a local mercury headquarters that bass pro directed me to. i asked the mechanic there and he told me to remove the screw from the fuel holder on each carb and flush it out with new fuel. i did that and it would start up but if you gas the motor, it would die. so i went back and he told me to rebuild the carbs with new gasket and clean it with carb cleaner when you remove it. so i did that and it worked, took it to the ocean and it ran like a champ. summer was over winter was coming so i left the boat in my back yard. i would start it every month or so or every 2-3 weeks when i have a chance, but the rainy and cold weather came in Socal with moodswings. so i wasnt able to start it up for about a month and a half, i attempted to start it again and it did the same thing. it would start but wont stay on or when i gas it, it wont stay on.

want to fix this boat so i can get ready to fish my local harbors this coming spring/summer.


any info is greatly appreciated.

 

[jdmjunkiemonkie]

Re: Cant keep the motor on 97-99 Merc 50 2 stroke

heres a video of me attempting to start it recently. sometimes it would stay on for a bit and sometimes it would just die right after you start it.


at the very end of the boat i tried to give it gas, but as you can see the motor dies when i release the throttle.

 

[Laddies]

Re: Cant keep the motor on 97-99 Merc 50 2 stroke

It's not running on 3 cyls and if cleaning the carbs fixed it last fall, probably cleaning them again will fix it again.

 

[Silvertip]

Re: Cant keep the motor on 97-99 Merc 50 2 stroke

And use a fuel system treatment like SeaFoam in every tank of fuel. Did you fully disassemble the carbs and inspect and clean every passage to make sure they were squeaky clean? Did you synchronize the carbs after to reassembled them. Did you set the float heights properly. Is the idle mixture set correctly. Are the fuel filter(s) clean. Is the fuel pump working properly. Are there air leaks in the fuel line, primer bulb and any connections. Does the primer bulb get sucked flat when the engine is running. Is there spark on each cylinder. That should give you a few things to look at.

 

[jdmjunkiemonkie]

Re: Cant keep the motor on 97-99 Merc 50 2 stroke

And use a fuel system treatment like SeaFoam in every tank of fuel. Did you fully disassemble the carbs and inspect and clean every passage to make sure they were squeaky clean? Did you synchronize the carbs after to reassembled them. Did you set the float heights properly. Is the idle mixture set correctly. Are the fuel filter(s) clean. Is the fuel pump working properly. Are there air leaks in the fuel line, primer bulb and any connections. Does the primer bulb get sucked flat when the engine is running. Is there spark on each cylinder. That should give you a few things to look at.

i am new at rebuilding boat carbs so most of the things i didnt know i have to do or knew i had to do it.

okay i will put some seafoam into the fuel tank
i disassembled the whole carbs and sprayed with carb cleaner replacing every gasket, went through like 4 bottles of carb cleaner.
how would i synchronize the carbs?
i just put everything back together not thinking i would have to do the float height.
no idea how to set the idle mixture correctly
fuel filter i have a new one waiting to install it.
need to double check the fuel pump
prime bulb is brand new hose is brand new, no leaks what so ever. prime bulb doesnt go flat when engine is running.
spark in every cylinder.

 

[quicktach]

Re: Cant keep the motor on 97-99 Merc 50 2 stroke

fuel tank vent working ok and open? Any water separating filter ? Good quality gas and fresh ?

 

[jdmjunkiemonkie]

Re: Cant keep the motor on 97-99 Merc 50 2 stroke

fuel vent working properly
no water separating filter
brand new fuel, i emptied out the old fuel and put fresh new shell 87 octane gas.