Carbs leaking fuel 1988 force 125hp

Josecaliente

Seaman Apprentice
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Jul 13, 2018
Messages
44
Good morning all,
Im currently working on a 1988 force 125 outboard. The carbs have been leaking fuel since the first day I purchased it. So far I’ve purchased the rebuild kit and installed it (gaskets and new needle). I also adjusted the floats. The carbs still leak though. The only problem I’ve fixed with these new parts and adjustments is the primer bulb will get hard now prior to initial startup. Any ideas what else I should check or replace? Thanks in advanced.
 

puffitu

Chief Petty Officer
Joined
Dec 30, 2018
Messages
555
Adjustment on floats -13/32 if you didn’t know. I had an issue where I found tiny little paint chip in each one of the ports where the needles open and shut; the size of a grain of sand and very hard to see. Made fuel spurt out and flood out the motor. Take the carbs apart and blow compressed air deep into and through these carbs as the insulation or liner becomes brittle over time and breaks up into dust then gets sucked into the carbs.
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
A word of caution. If the material that the floats are made of are the hard foam stuff, they may not be a buoyant as they were when they were new. This will affect the float level setting. You have to either replace them or if using the old floats, set the float level so that they are about 1/16th of an inch farther away from the body of the carb than what the manual indicates. The replacement floats that I've seen are plastic and the tab isn't really adjustable. I found a set of brass floats and they work great.
 

jerryjerry05

Supreme Mariner
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May 7, 2008
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17,923
Are the needles solid or have a rubber tip?
The solid ones: the seat can be damaged from the chemicals used in cleaning??
Or the seat can be gone from cleaning.
The rubber tip needles: the tip can be damaged or something in the seat??
 

Josecaliente

Seaman Apprentice
Joined
Jul 13, 2018
Messages
44
A word of caution. If the material that the floats are made of are the hard foam stuff, they may not be a buoyant as they were when they were new. This will affect the float level setting. You have to either replace them or if using the old floats, set the float level so that they are about 1/16th of an inch farther away from the body of the carb than what the manual indicates. The replacement floats that I've seen are plastic and the tab isn't really adjustable. I found a set of brass floats and they work great.
I purchased the replacement plastic floats and they made my engine run horribly. So I put the old rubber ones back in. @pnwboat
 

Josecaliente

Seaman Apprentice
Joined
Jul 13, 2018
Messages
44
Are the needles solid or have a rubber tip?
The solid ones: the seat can be damaged from the chemicals used in cleaning??
Or the seat can be gone from cleaning.
The rubber tip needles: the tip can be damaged or something in the seat??
@jerryjerry05 i replaced the needles. The old ones were rubber tipped but the replacement ones that came in are metal tipped
 

puffitu

Chief Petty Officer
Joined
Dec 30, 2018
Messages
555
Yup. And I also read somewhere that if you’re using original or old floats; they tend to loose buoyancy therefore it was suggested to go 1/16 more but I haven’t verified that, although it completely makes sense.
 

jerryjerry05

Supreme Mariner
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May 7, 2008
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17,923
The needles you replaced need to be the same as you took out,
put the old ones back in the new are for a different carb :(
 

MrMarty51

Seaman
Joined
Aug 4, 2020
Messages
51
I have rebuilt a lot of the quadrajet automotive carbs. They all have the styrofoam floats that gets fuel logged. I even have a scale to weigh them with and the GM book gives the weight of the different styles of floats.
I used to weigh the floats, order new one and after verifying the new float fit, carve open the foam float to see how deeply the fuel penetrated onto the foam, surprisingly, quite a ways in most of them. No wonder the poor old beast was blowing black smoke. LOL
Replace them foam floats woth a brass unit, keeping in mind that any other material will tend to be a little heavier, and yes, usually a brass float will be closer to the foam floats weight. I never had a problem using factory spec for setting the brass float to, but, that was on a big Q-jet carb and being slightly off probably did not affect them as much as it would a tiny boat carb.
 

Josecaliente

Seaman Apprentice
Joined
Jul 13, 2018
Messages
44
I have rebuilt a lot of the quadrajet automotive carbs. They all have the styrofoam floats that gets fuel logged. I even have a scale to weigh them with and the GM book gives the weight of the different styles of floats.
I used to weigh the floats, order new one and after verifying the new float fit, carve open the foam float to see how deeply the fuel penetrated onto the foam, surprisingly, quite a ways in most of them. No wonder the poor old beast was blowing black smoke. LOL
Replace them foam floats woth a brass unit, keeping in mind that any other material will tend to be a little heavier, and yes, usually a brass float will be closer to the foam floats weight. I never had a problem using factory spec for setting the brass float to, but, that was on a big Q-jet carb and being slightly off probably did not affect them as much as it would a tiny boat carb.
The only replacement floats I found were plastic and they were twice the size and kept getting stuck
 

jerryjerry05

Supreme Mariner
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May 7, 2008
Messages
17,923
Myself, I've never seen a water/gas logged float from the 125
The 85/90 had brass floats and every now and again they would
spring a leak and cause problems.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
The kit was an OEM kit. The old needles were definitely bad the rubber was deformed
Is it still leaking ??
Take a pic of the needles next to a ruler, post it.
I might have them and can send them to you free.
The backfire could be from too much fuel or the timing's off?
Or it's sucking air from somewhere? Do the starting fluid test, start motor and spray SF around the intake side of the motor, that includes the port covers and carb bases. If the SF makes a difference??? then it's sucking air
someplace???
.
 
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