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1Back to top Go down   Odd leak from overflow Empty Odd leak from overflow Mon Mar 06, 2023 7:36 pm

brianpen

brianpen
Silver member
Silver member
My 94 K75 has a drip leak from the fuel tank overflow tube about the rate of an ounce per 8 hours. My suspicion is that there is a pin hole in the line somewhere in the tank that allows fuel to enter it. Has anyone experienced this? I'm thinking that if I plug the overflow hose at the exit of the tank, it shouldn't be a problem. Is there something I am missing in this thinking?

    

2Back to top Go down   Odd leak from overflow Empty Re: Odd leak from overflow Mon Mar 06, 2023 7:45 pm

Rick G

Rick G
admin
admin
You will need to find and fix the problem because just blocking the overflow line will likely cause you problems with a vacuum forming in the tank and fuel flow will be limited. The pump will pump big pressure and could cause the tank to cave in before the engine staves for fuel.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

3Back to top Go down   Odd leak from overflow Empty Re: Odd leak from overflow Tue Mar 07, 2023 11:02 am

brianpen

brianpen
Silver member
Silver member
Rick,
 I was afraid of that answer.
 I wonder if I can apply compressed air to the outlet and feel for a leak in the tank line (empty of course)? 
Any suggestions are appreciated.

    

4Back to top Go down   Odd leak from overflow Empty Re: Odd leak from overflow Tue Mar 07, 2023 11:38 am

Point-Seven-five

Point-Seven-five
Life time member
Life time member
First thing comes to mind is whether it leaks all the time, or only when the fuel is above a certain level.  That might help identify what part of the tank you need to concentrate on. 

The problem with finding the leak with air pressure is that the line is not an overflow, but the tank vent, and it connects to the "burrito" in the upper part of the tank.  The "burrito" has several openings to allow air and some fuel to enter and leave it.  Obviously, these holes will make it difficult to spot an air leak in the tube. 

As far as the probable location of the leak, the first place to look is the spot where the tube exits the tank.  Corrosion or a broken weld could cause your problem.  Fortunately, that would be the easiest to repair.  I really doubt that there is a hole in the tube as I can't imagine a way to make one where the tube runs in the tank. 

It is also remotely possible that the problem is a bad o-ring in the plate that holds the fuel level sensor.  There's a slight chance that the tank insulation is guiding the leaking fuel from the plate to the spot where the vent spigot is located.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

5Back to top Go down   Odd leak from overflow Empty Re: Odd leak from overflow Tue Mar 07, 2023 11:58 am

brianpen

brianpen
Silver member
Silver member
.75
Thanks for the insights. I verified that it is in fact coming out the overflow. I agree that the likely trouble spot is at the exit. 
I have used a two part epoxy (like chewing gum) on the outside with good results. What would you recommend as a sealer for the inside?

    

6Back to top Go down   Odd leak from overflow Empty Re: Odd leak from overflow Tue Mar 07, 2023 12:25 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Make very sure that's where the leak is first. 

Personally, I am reluctant to put any kind of sealer or coating inside a fuel tank.  Gasoline and ethanol(especially that damn ethanol) are powerful solvents that seem to turn anything I put in the tank to goo floating around with the fuel.

I would just be very sure that the spot where I putting the patch was a perfectly clean as I could get it.  Remove all the paint and wash the area a couple times with rubbing alcohol.  JB Weld makes an excellent tank sealant that many have used with good results.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

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