84 mercury 7.5 carburetor problems

BLM762

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Mar 30, 2015
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I will start by saying lots of useful info here great forum
I picked up a 84 merc 7.5 knowing the carb needed some work
I got a gasket kit cleaned and rebuilt the carb new needle valve except I did not get a new float
I adjusted the float to where you could barley blow through the needle valve hole with it open put it on pump the ball up gas just over flows took it off adjusted to where it you couldn't blow through it put it back on couldn't get fuel in the carb take it off tweek the float level some more get it started it would run for a sec then pump fuel out of the main jet like the needle wasn't closing I have messed with the carb for hours back and forth must have taken the carb off and back on 20 times had it running great idle and everything but gas would still leak out the front of the carb so I put a new needle valve in still way to much gas or none I have tried everything and don't know what to do several guys I have talked to have never came across this shy of getting a different carb not sure what to do
 

racerone

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?????---Turn carburetor upside down.----Adjust float so that it is level and install carburetor.
 

BLM762

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Mar 30, 2015
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?????---Turn carburetor upside down.----Adjust float so that it is level and install carburetor.
pretty sure I tried that let way to much fuel in and overflowed maybe its binding on the spring on the backside of the needle the metal tab is a little bit of an angle
its set about a 1/16 gap looking sideways from the bottom of the carb to top of float right now
shy of getting a new float or diff carb not sure what to do
 

BLM762

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I have another question pertaining to the fuel fittings
the fuel fitting that bolts to the lower cowl has a metal stem that is supposed to have an oring on it will that affect the fuel delivery sytem or is that more for keeping the rod in place
 

quicktach

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Aug 24, 2012
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Make sure the float and the carb body are level and parallel when the carb is upside down. Try no angle on the metal tab.While you put in a new needle valve, how is the seat?
 

BLM762

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Make sure the float and the carb body are level and parallel when the carb is upside down. Try no angle on the metal tab.While you put in a new needle valve, how is the seat?

The seat looks great as far as I can tell with a flashlight
I tried again today making sure it was level and the tab was almost straight upside down no luck runs for a second the gas pukes out the front of the carb honestly thought it might work
I guess I two options now try a new float if that will help not sure or get a used carb and start over
 

BLM762

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I also was thinking who knows what someone else has done to the carb when I got the motor and took the carb apart it looked fine except the tab on the float was bent quite a bit I did have it running and idleing just fine the other day except gas was dripping out the front of the carb obviously that's not right so I guess I have narrowed it down to the needle seat and or the float not sure
 

BLM762

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well after talking to a few places im thinking the reeds are leaking letting air by and causing the carb to overflow
sounds like a not so fun and expensive fix

ETA but maybe not it just pores gas out the carb when it dies doesn't spit gas out when its running
 
Last edited:

quicktach

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Does the carb float move freely on it's shaft? Is there anything rubbing against the float assembly when it's in it's correct position ...rightside up? You may want to try another float.And yes, maybe a used carb.
 

BLM762

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Does the carb float move freely on it's shaft? Is there anything rubbing against the float assembly when it's in it's correct position ...rightside up? You may want to try another float.And yes, maybe a used carb.

Yes it moves freely and doesn't seem to be rubbing so I could have bought a new float for $12 but opted to pick up a used carb yesterday instead for $40 cleaned it up a little bit threw on a few new seals from the other carb put it on two pulls later runs and iddles great and doesn't leak guess the old carb is for parts now
Thanks for the replies
 
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