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help with carburetor 50hp mercery outboard

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  • help with carburetor 50hp mercery outboard

    I have a 50 hp outboard merc on a 24' pontoon year 84. Im looking for a link or something to tell me how to remove the carbs. The bottom one seems next to impossible to get to. I know small engines but this is my first boat motor. The is something keeping the fuel from getting into the carb. I had the same problem with the top one, but after removing the side plate with the fuel line, it straightend itself out. I tried this with the bottom, which was hobbible to do. I need to take the carb off and give it a kit and clean it out. Any help please. I'm about to my witts end trying to figure this out.

  • #2
    Re: help with carburetor 50hp mercery outboard

    Been there, done it 3 times ... I'm with ya brother!

    1. remove the power plug from the motor and then remove the starter ... easy job, 1 wire and 4 bolts.
    2. remove the choke linkage and the electric choke plunger. To remove the choke linkage, you have to twist it to get it out of the slot, don't worry it's pretty tough plastic. If it was going to break, I would have broken it. Remove the phillips head screw and spring, the electric choke plunger pulls right out.
    3. remove the top carb first, be VERY careful with the plastic link between the carbs, remove the linkage screw in the lower carb, lift the top carb as you remove it. If you break it, fortunately its still available ... guess how I know.
    4. try a couple different wrenches when trying to get the carb nut off of the lower carb that is closest to the starter, the right wrench is easy, the wrong wrench is a PITA, a few degrees difference in wrenches makes a HUGE difference! You need the right box-type wrench. Having the top carb and starter out of the way is key.
    5. after you have the carbs off, remove your fuel bowls, you will probably find one that is dry. If you do not remove your fuel line and run your motor out of fuel EVERY time you use the boat, your rubber tip on your needle valve will swell and stuck in the seat, therefore keeping you from getting fuel in the carb. This can happen in less than a week .. gotta love this ethanol crap!
    6. pluck your stuck needle out of the seat with needle nosed pliers

    Don't let the job scare you, this is my first outboard too, I know 2 stroke dirtbikes, not much different. I was in your exact situation, I can do it in my sleep now ... and probably have! If you have Tillotson carbs and you have removed the blue fuel inlet pieces, you may need to replace them. Once removed, sometimes there is NOTHING that you can do to keep them from leaking, even with new gaskets .. they deform over time. I spent a whole lot of time trying, it's not worth it and didn't work.

    They make an ethanol compliant needle, do yourself a favor and replace them. Sierra carb kits about $5.60 each, Sierra fuel pump kits about $6.50 each, you need both since all fuel pump parts are not included in the carb kit. Replacement Tillotson blue fuel inlet pieces, $5 each. Buy it all, do it once. The Sierra kits do not include the welsh plugs required to pull out the idle circuitry, I didn't need it with mine.

    I rebuilt my carbs and pumps but have not yet replaced my needles. I pull my fuel line every time and run it out of fuel. I have never once had this problem again since doing so. Running the bowl dry allows the needle to drop and therefore won't stick in the seat.
    '78 Sylvan Sea Master
    '77 Merc 500, 4 cylinder Thunderbolt
    55# Minn Kota V2 Powerdrive

    Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time on the water than taking care of the lawn.


    • #3
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      Re: help with carburetor 50hp mercery outboard

      Thanks for the encouragment. the bottom carb has been my biggest problem. I guess I better hunt down a wrench. Thnaks for the info. I will apply it today.