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Carb Fuel Leak


rstrueman's Avatar
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01-13-03, 09:37 AM   #1  
rstrueman
Tecumseh Fuel Leak

I have a Mastercraft Snowblower with a Tecumseh 8HP H80 Engine. My problem relates to fuel leaking/dripping from the set screw on the bottom of the carb while the machine is sitting in my garage. The machine starts and runs okay, lots of power. I even closed off the fuel valve and let the machine run until it ran out of fuel. I place a stainless steel bowl under the carb area and after three days I am still empting the leaked fuel back into the tank. I have replaced the set screw gasket and seal twice to try and correct this with no luck. Am I into a carb overhaul or could this be related to an inlet line problem or something else I have overlooked ? Thanks for any help you can provide.

 
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01-13-03, 07:57 PM   #2  
Hello rstrueman!

Sounds like you're gonna have to rebuild the carb. I think you have a leaking needle and seat. Replace them both, and a new float would be a good idea while you're in there. It also sounds like your fuel shutoff is not fully sealing off the flow of gas.

Let us know how it goes!


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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01-13-03, 10:26 PM   #3  
Tcumcman
Leaking Carb via Power Screw

If you've replaced the gasket around the power adjustment
screw that seals it to the float bowl, then the gas is coming
through the power screw itself, OR....there is a potential
pinhole or crack in the float bowl. You can purchase the
main adjustment screw SEPERATELY, and it comes in a
repair kit, too. Give us the spec number that goes with
the H80 (that's an "old girl") and I'll tell you what you need.

Tcumcman

 
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01-14-03, 01:03 AM   #4  
I suggested the needle valve seepage because usually when one seeps, the gas makes it's way down the sides of the bowl almost invisibly and drips off of the screw at the bottom. I do agree that it could also be leaking through a pinhole in the bowl. Sometimes when a few drops of water are present in the bottom of a carb bowl, it rusts on the inside, and eventually develops a leak. This can be easily seen upon removal of the bowl.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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01-14-03, 02:17 PM   #5  
rstrueman
More Information

Thanks very much for the quick reply, I think that more snow is on the way and I need to get this fixed.

I'm now suspecting a leaking float. Would this cause an overflow condition out through the air inlet and down the side? The model # is HM80-155293K Serial # 5249D. If I get a carb kit will it come with a new float ? Also what would the part number be for the kit that I need ?

Thanks again.

 
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01-14-03, 02:53 PM   #6  
Tcumcman
Carb Repair

Carb kit is 632347. Float NOT included. You'll need a
632019 float, too. The leak you describe can only be
from fuel running THROUGH the float bowl. This is ONLY
caused by non-sealing needle/seat OR bad float. If there
was water in your float bowl at one time, and allowed
to freeze in there, the resulting expansion will CRUSH
the float. This may very well be your problem....A stopped
up atmospheric vent passage can also cause this, but is
not likely the problem considering the diameter of the
passageway. This ONLY happens in the WORST CASES
of varnished gas, OR....if someone has PLUGGED it to
keep gas from running out it. I've seen that happen !!

Tcumcman

 
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01-15-03, 10:36 PM   #7  
miklstel
Leaking carb

I have the same problem with a Briggs engine. I have rebuilt the carb and replaced the float and it still leaks. Tell me more about the atmosphere vent. Where is it located? Sounds like mine might be plugged.

 
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01-16-03, 01:04 PM   #8  
rstrueman
I was able to get the kit and float. I was wondering if someone could tell my the part number for the gasket between the carb and engine intake. It was not included with the kit, I guess they expect you to overhaul the carb while still on the engine. Very difficult to work on this thing upside down!!

Thanks,

 
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01-16-03, 02:45 PM   #9  
Tcumcman
Carb Gasket

Gasket between carb and intake pipe is 33263. Intake pipe
to engine block is 27915A. The 33263 gasket IS included with
a NEW carb, but not in a carb kit.

Tcumcman

 
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01-16-03, 04:09 PM   #10  
rstrueman
Thanks very much for your help, I will let you know how I make out with this. Weekend Project between Hockey !!!!

 
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01-25-03, 08:48 AM   #11  
rstrueman
It is Fixed !!!!!!

Just to let anyone who's interested know,

I removed the carb, cleaned it up replacing the parts supplied in the overhaul kit. I also replaced the float. After re-installing on the engine it now works perfectly with no more fuel leaks. Some information from another web site, www.lawn-mower-shop.com, was also helpful. It mentioned that with tecumseh carbs the orientation of the clip which holds the needle valve to the float is important. The open side of the clip must face/point to the intake side of the carb in order to prevent leaks. I know that this makes no sense however mine was facing the wrong way and the float did not appear to have a leak although I replaced it anyway.

Hope this helps others who have similar problems,

rst.........

 
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