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Mercury 50hp carb float adjustment

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Adam4ntium

New member
Hello,
I have a 1984 mercury 50hp 4-cylinder and I'm wondering where to measure to set the floats on my carbs. It seems like any time I look things up online, I get results for the 3-cylinder. Also, the needles have a spring on them and I've never set a float with a needle like that. Everyone says the float should sit level with the carb body, but the springs hold them at a pretty decent angle and I'm not gonna bend that much out of those little tabs. I assume you measure from the carb body to the casting line on the float on the opposite side from the hinge pin? And where can a guy get a good physical paper manual for these things nowadays. I've heard some of the manuals are garbage depending on which brand you get. Thanks
 
I need your serial number to see which carbs you have, there were two different style carbs. Basically they were the side bowl or center bowl design.
 
racerone said:
What is your motor doing / not doing that leads you to float adjustment
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I was really just taking them apart to clean them and want to make sure they are still adjusted correctly. I bog down when I try to give it throttle and it starts to sputter and jerk. It may be the fuels lines more than the carbs considering there's gas all over the front of the motor, but the carbs really don't seem to be plugged or anything.
 
fitz73222 said:
I need your serial number to see which carbs you have, there were two different style carbs. Basically they were the side bowl or center bowl design.
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I was gonna post a picture of the carbs, but these new phones won't take a picture where the file size isn't too big to post.
 
The float is adjusted by bending the metal tab at the rear of the float to set the height, with needle and seat assembled in the carb body with carb upside down and the float top surface level with the casting. There maybe a little clip that connects to the needle and slides over the flat metal stamping. I usually hang the needle with clip and lower it into the seat as I slide in the hinge pin, then set the height. Fairly easy to do but I've done many of then so it may take a little practice for you.
 
fitz73222 said:
The float is adjusted by bending the metal tab at the rear of the float to set the height, with needle and seat assembled in the carb body with carb upside down and the float top surface level with the casting. There maybe a little clip that connects to the needle and slides over the flat metal stamping. I usually hang the needle with clip and lower it into the seat as I slide in the hinge pin, then set the height. Fairly easy to do but I've done many of then so it may take a little practice for you.
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That's where my hangup is. There is no clip to slide the needle into, just a flat metal tab. The back of the needle has a coil spring sticking out of it that is about 1/4" long that contacts the tab. Because of this, the float sits nowhere near level. Can't find any videos of carbs with a needle like these.
 
Adam4ntium said:
That's where my hangup is. There is no clip to slide the needle into, just a flat metal tab. The back of the needle has a coil spring sticking out of it that is about 1/4" long that contacts the tab. Because of this, the float sits nowhere near level. Can't find any videos of carbs with a needle like these.
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I've never seen a needle with a spring sticking out of it. These were the needles that were in the carb when you took it apart?
 
Well I stand corrected. The needle for that engine does have a spring in the end of it for either the warlboro or the tilliston version. Do you have the float installed the correct way up? Look at the parts diaphragm for the carb on this website for your serial number.
 
racerone said:
Perhaps this is not a fuel / float / carburetor issue.-----Any other trouble shooting done ?
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Not yet. I got a compression tester and ordered some new plugs and wires. I'll be checking through the whole ignition system next to make sure everything else is working. Carb clean up was just the first, easiest thing. I had to pull the starter to get the carbs off, so I'll be checking all the other stuff once I get them back on and get my wiring reattached. Hopefully it's not a compression issue.
 
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