[AT] [Farmall] Super A Carb Leak

[charlie hill]

Ben the thing has to be spotlessly clean inside.  I rebuilt a M-S  carb a 
while back.  I was 100% sure it was right.  I put the thing back on the 
tractor and it wouldn't run without the chock pulled half open.  My neighbor 
is a pretty good mechanic.  He heard it run and said  "you've got trash in 
the carb".  I told him it couldn't be.  He shook his head and said "trash in 
the carb".   I pulled it back apart, looked it over from one end to the 
other, ran carb cleaner through it again, and blew it out with air again.  I 
never saw a thing come out of it.  I put it back together and it ran like a 
clock.   That's got nothing to do with your problem other than it 
illustrates the need to have the carb very clean.    When you are absolutely 
certain it's clean, clean it one more time, check the valve and seat for 
scratches or grooves.  You might need to get some lapping compound and seat 
it manually.  Make sure there isn't anywhere or anyway the float can hang.

If anyone can think of anything I've missed or I'm wrong about please speak 
up.

Charlie

--------------------------------------------------
From: "Ben Wagner" <supera1948 at gmail.com>
Sent: Wednesday, July 07, 2010 3:26 PM
To: "Farmall/IHC mailing list" <farmall at lists.antique-tractor.com>
Cc: "At" <at at lists.antique-tractor.com>
Subject: Re: [AT] [Farmall] Super A Carb Leak

> On 7/7/2010 12:29 PM, Barney Van De Weert wrote:
>> The needle and seat control the level of gas in the carb bowl. If it over 
>> flows
>> the gas drains out of the hole by the choke. The float, needle and seat 
>> are
>> probably still suspect, the fact it leaks after you run it indicates the 
>> needle
>> is not seating correctly or the float is sticking and not pushing the 
>> needle
>> into the seat.
>>
>>
>> Also if there is any dirt at all coming from the tank, it can cause them 
>> to leak
>> as well. Make sure the fuel bowl is clean and has a screen installed
>> correctly in it.
>>
>> I have had brand new needles and seats that still leaked.
>>   Barney Van De Weert
>> 3828 Heartwood St
>> Uniontown OH 44685
>>
>>
>> bbvande at yahoo.com
>> Cell# 330-760-5988
>>
>>
>>
>>
>> ________________________________
>> From: Ben Wagner<supera1948 at gmail.com>
>> To: At<at at lists.antique-tractor.com>; Farmall/IHC mailing list
>> <farmall at lists.antique-tractor.com>
>> Sent: Wed, July 7, 2010 9:16:06 AM
>> Subject: [Farmall] Super A Carb Leak
>>
>> Hello,
>>
>> Thank you for all the imput.  The carb leaks from the drain in the choke
>> housing.  First off, if you have had the same problem and figured a  way
>> to fix it, I really would like to know how you did it!
>>
>> Here's a clue that maybe someone more experienced than me could
>> decipher.  The carb, once I rebuild it, doesn't leak.  In fact, I left
>> the gas on just to check, and two hours later it still didn't leak.  But
>> once I run the engine, it leaks.  What would cause this?  The float,
>> though it is brand new, I tested yesterday, and it is sound.  The
>> needle/ seat I tested, and replaced.
>>
>> Would this fact of when the carb leaks make a difference in what the
>> problem is?
>>
>> Thanks,
>> Ben Wagner
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>>
>>
>>
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> You said that you had a brand new needle/seat leak.  What did you do to
> fix the leak?
>
> I performed a test where the upper halve of the carb (with float,
> needle, seat, etc) is suspended over a clear bowl.  I turned the fuel on
> to see if the float shuts off when the level in the bowl gets high
> enough.  The float seems to shut the fuel off, though I can't tell
> whether or not there is a small leak.
>
> So what you are saying is that I start the engine, it sucks gunk from
> the sediment bowl that sticks to the seat, not allowing the needle to
> stick.  Wouldn't I be able to see the gunk when I disassemble the carb?
> I have had paint in the seat before, but not the last couple of times it
> has leaked.
>
> Thanks for your help.
> Ben Wagner
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