Mercury fifty classic 2 stroke losing power also need help with set up carburetor

[Alumarine]

Hi speedy and welcome. You should start a thread of your own for best results.
Try pumping the bulb when it starts to stall. If that helps you need to rebuild the fuel pump.

 

[speedyaction]

Hi. i bought speedboat with mercury fifty classic with was no used for long time. two carburetors was removed so i did't test engine when i bought it. after cleaning and putting back carburetors i start engine and went very well. so i put my boat to water and was trying to test it. so i did. i went full throtle but after 5 min engine slow down and don't want to go faster. looks like losing power. i don't no what can be wrong. Anybody had this same issue with this engine? if is on low raves works ok only when i go full speed is slowing down. also how to set up carburetor ? there is screw i can twist left and right but i don't no how many turns.

 

[speedyaction]

Hi marc c. thanks for reply? i had lots of oppinion abou that engine. one guy who fixing engines told me is overheating problem but i don't belive mechanics who want 80 pounds for 1h repair so may he want rob my money. i just clean carburetors with white spirit. i remove all parts and make it so clean but i don't no how to set up this screw on spring. i don't no how many turns need to do to set up proper way. i no how to fix car engines but no boats. i replace new filter and check spark and all good but still this same problem. can you help with carburetor setting. also tomorrow i will have look on my petrol pump. my engine serial number is : 9459889 i don't no how can i found replacement parts for my pump? if you can help me that will be awesome. thanks for your time

 

[GA_Boater]

Moved some of you other posts to this thread speedy.