# Carb Help



## ColoradoDoug (Feb 18, 2016)

I bought an old Craftsman snowblower with a Tecumseh engine. Model 536.882502

It was not running when I got it. I removed the carb and cleaned everything. Put it back on, put some gas in the tank and I got a drip from the front of the carb by the choke. 

Why? Float bad? Needle stuck somewhere? Ideas?

Thanks


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## bwdbrn1 (Nov 24, 2010)

Cleaning old carbs can be an exercise in frustration some times. Just when you think you have everything cleaned up, they leak. It might take another cleaning, and maybe a kit, which should include all new gaskets and float needle, if you didn't already install one. From what others say, it might just be easier and cheaper to buy a new replacement carb.


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## bad69cat (Nov 30, 2015)

Could be - the gas we use is not very stable these days..... plus if it had ethanol in it it sucks water in and corroded/rusts the carbs. You need to make sure the needle and the seat/rubber are in good shape and that the float is adjusted tight and working (no holes or leaks). If those things are good, it shouldn't leak/flood. Try adjusting the float a little higher (closing earlier) see if that helps


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## td5771 (Feb 21, 2011)

Dripping from the mouth of the carb means the fuel level is too high. 

You need to set the float level. With the bowl off and your holding the carb upside down the float should be 11/64 from the flange the bowl gasket goes around. 

Occasionally that is still too high and you will need to make it a little lower.


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## ColoradoDoug (Feb 18, 2016)

Adjust float level by bending the tab holding the needle?


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## td5771 (Feb 21, 2011)

Yes. When holding it upside down the tab will rest on the needle. Bend as needed.


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## Motor City (Jan 6, 2014)

Did you install the needle seat in the correct direction? their is a slight groove on one side. And it faces downward.


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## ColoradoDoug (Feb 18, 2016)

I did install the gasket the correct way. I took everything apart again, rechecked holes, and gaskets. Reassembled, bolted it on and it fired right up and ran okay for a minute or two and then started spilling gas again.


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## skutflut (Oct 16, 2015)

ColoradoDoug said:


> I did install the gasket the correct way. I took everything apart again, rechecked holes, and gaskets. Reassembled, bolted it on and it fired right up and ran okay for a minute or two and then started spilling gas again.


You might want to try shutting off the gas at the fuel shutoff, then removing the bowl while the carb is installed. If you don't have a shutoff valve, then pinch the fuel line with pliers or vice grips gently to stop the flow.

Have a container to catch fuel under the carb and then open the gas shutoff and hold the float up to see if it stops the flow. ( might need three hands to do this without making to big a mess). If the flow stops when you hold the float up (needle pressing into seat) then you need to do some more adjustment to float height. Also check the float is not sticking as it raises and lowers. If fuel still flows with the float held up, then either the needle or seat is damaged or there's still some crap in the seat or under the seat keeping it from sealing.

It sounds like the float height is off if you are getting overflow with the engine running. Check the gasket at the main jet as well where it holds the bowl onto the carb. That could be leaking. Does your carb have a drain port in the bowl near the main jet? If so, another thing to check. I assume you checked that the float itself doesn't have a leak and is not full of gas?


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## ColoradoDoug (Feb 18, 2016)

I will check some more in the morning. I might have to check the float without the bowl. The carb has new gaskets/o-rings. I checked the float and it has no leaks and nothing inside. This snow blower has no fuel shutoff valve, but I think I will get one to make things easier.

More testing in the morning and I will update.

Thanks


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## skutflut (Oct 16, 2015)

ColoradoDoug said:


> This snow blower has no fuel shutoff valve, but I think I will get one to make things easier.
> 
> Thanks


Agreed, it will be easier, plus you can shut it off after working the machine, and not worry about leaks stinking up the garage.


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## ColoradoDoug (Feb 18, 2016)

Well, l installed the shut off valve. I removed the bowl and depressed the float to keep the fuel shut off ( light pressure). Fuel did not come out. If I let off, I got fuel. I also cleaned the tank again. Lastly, before reinstalling the bowl, I checked the float level. 

Turn on gas after installing and it begins flooding again. 

It's getting very frustrating!

I am not sure what else to do. Try cleaning tank again and carb? Float level should be good, if anything I have it adjusted to the extreme of low fuel level in the bowl.


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## Motor City (Jan 6, 2014)

What float does the carb have? Is it brass or plastic? The brass will get leaks and start to fill inside with gas. This could be a possibility. And just a stupid question, you did remove the old needle seat? Make sure the seat is fully down the throat.

What I do, when I rebuild a carb, is I turn the carb over in my hand a blow lightly thru the fuel inlet o make sure their is no leaks. Its a quick check, before I mount the carb on the engine.


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## ColoradoDoug (Feb 18, 2016)

Brass float, and I tested it to make sure it did't have any holes. 

I fully seated the new o-ring and made sure it was in the correct way.


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## Motor City (Jan 6, 2014)

ColoradoDoug said:


> Brass float, and I tested it to make sure it did't have any holes.
> 
> I fully seated the new o-ring and made sure it was in the correct way.


So you shook the float and heard no liquid? I would consider getting a plastic float. Don't get too frustrated. You should be able to figure this out. Do as I said in my last post. test the float for closing, before you remount the carb.


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## ColoradoDoug (Feb 18, 2016)

I have not tried turning it upside down and blowing in the fuel inlet port. I will try that. I did remove the bowl and applied light pressure and could stop fuel flow. 

I have shaken the removed float a few times and nothing is inside. I have put it in a jar submerged in gas and it never sinks.


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## skutflut (Oct 16, 2015)

If you have the float set right, then the leak has to be coming from the bottom gasket where the main jet screws in, or from the drain valve if you have one. But your description says its leaking out the throat near the choke which says the float is still not set right.

I don't know if you have watched this video, from Donyboy73. but it shows the process for rebuilding and setting float height in part 2. Also shows the details of replacing o rings etc. This is for Tecumseh 4-7 HP engines.


part 1 



part 2


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## ColoradoDoug (Feb 18, 2016)

It's not leaking from underneath. I can watch it start to flow right out of the throat of the carb.


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## Jackmels (Feb 18, 2013)

I got tired of wasting time and money on rebuilds, especially when a repop adjustable carb is only $20.


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## skutflut (Oct 16, 2015)

ColoradoDoug said:


> It's not leaking from underneath. I can watch it start to flow right out of the throat of the carb.


Check out part 2 of the video, around 7 minutes in where he gets into the setting the float height. Is that the process you followed?


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## wheelhorseboy (May 30, 2014)

Does your carb have this vent hole, if so have you made sure it is clear? If this little vent hole is not clear, it will pour gas out the carb.


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## bad69cat (Nov 30, 2015)

^^ Good point!! Easily overlooked little vent hole...... push a thin wire through it to be sure.


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## 404 (Feb 1, 2015)

wheelhorseboy said:


> Does your carb have this vent hole, if so have you made sure it is clear? If this little vent hole is not clear, it will pour gas out the carb.


I agree with you, but why does that happen? I have never figured it out.


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## alleyyooper (Sep 12, 2015)

I soak my torn down carbs in Lacquer thinner because it works and usually is cheaper than a decated carb cleaner. Blow it out with compressed air. you can by cans of it if you don't have a air compressor at the electronics section of like Wal Mart. I also buy pipe cleaners at the dollar store and use them to probe thru orifices. 
todays mfg. companies do not take the care and do inspections like they did once upon a time. Take a old valve in seat needle and put a bit of extra fine rubbing compound on the tip and twist it around in side the seat a bit to make sure all the little burs and mill marks are smooth. Remember to clean the seat after doing this.

Have never had a carb this method didn't work on.

*How to test a brass float properly.*

Examine the floats for any obvious damage and the float chambers for signs that the floats have been rubbing on the sides. Check the float operation by gently lifting with a finger to make sure nothing sticks or binds.
Remove the pins that hold the floats. Carefully remove the floats. The needle valves will usually come out as well, so check them for wear at the tips, then be sure to slip them off the float tangs and put them back into the seats for safekeeping.
Hold a float next to your ear and shake it. If you hear gas inside, the float has an obvious leak. *Reveal less-obvious leaks by grasping the float by the tang with a pair of pliers and submerging it into a pan of very hot water. A stream of bubbles will also indicate a leak.* Leaking and gas-saturated floats must be replaced or repaired.


 Al


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## ColoradoDoug (Feb 18, 2016)

wheelhorseboy said:


> Does your carb have this vent hole, if so have you made sure it is clear? If this little vent hole is not clear, it will pour gas out the carb.


I do not have the vent, just one bolt with adjusting screw in the middle.


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## ColoradoDoug (Feb 18, 2016)

I removed the carb again today, checked float level, recleaned everything and reassembled. Turned on fuel and started the engine. It ran fine, I shut off the fuel and it died. Then fuel (assuming from the bowl ) came out of the throat and started dripping for a little bit. It's like something is sucking the fuel out of the bowl. The shut off valve does stop flow from the tank. 

I am willing to take it off and give it one more shot, then it's time for a new carb. I have even ( at times) over adjusted the float to keep a low volume in the bowl. Nothing seems to be working. Could fuel be sucked up the middle jet, thus emptying the carb and spilling it out the throat?

While it was out I turned it upside down and blew into the fuel inlet and could not get air to pass by the needle, so I know it can seal it off when the bowl fills.


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## AL- (Oct 27, 2014)

ColoradoDoug said:


> I removed the carb again today, checked float level, recleaned everything and reassembled. Turned on fuel and started the engine. It ran fine, I shut off the fuel and it died. Then fuel (assuming from the bowl ) came out of the throat and started dripping for a little bit. It's like something is sucking the fuel out of the bowl. The shut off valve does stop flow from the tank.
> 
> I am willing to take it off and give it one more shot, then it's time for a new carb. I have even ( at times) over adjusted the float to keep a low volume in the bowl. Nothing seems to be working. Could fuel be sucked up the middle jet, thus emptying the carb and spilling it out the throat?
> 
> While it was out I turned it upside down and blew into the fuel inlet and could not get air to pass by the needle, so I know it can seal it off when the bowl fills.


You say, when you shut off the fuel the engine died and then fuel dripped out the throat "for a bit". 
MAYBE!!... the fuel shut off works and it shuts off and there is no leaking, if you again open it and it starts leaking a bit "steadily for awhile" this would mean fuel is by-passing the float needle or seat... (without the motor having been running there would be no vacuum, and no fuel left in the hose,etc.)
When the engine died from lack of gas of course the bowl would fill up at first when you open the fuel shut off valve again and the float should then rise and should shut the fuel off.


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## ColoradoDoug (Feb 18, 2016)

Okay, I got a new rebuild kit including a new float, followed the video, reinstalled and when I turn the fuel on it leaks. At the first, I primed the bowl and it spit a little fuel out of the throat. Then it began dripping pretty good. Shut fuel off and leak stops. Turn it back on and it leaks. The only thing I didn't replace was the bowl itself. Can that expand beyond specs and possibly cause a leak? Before I installed the bowl, I blew into the fuel inlet with the carb upside down and could not get air to flow through when the needle was seated. 

Should I get a new bowl and retest? When viewing the throat of the carb, I can put a rag at the opening and stop the flow, so I know it isn't coming from around the bowl gasket. I also don't see fuel coming out of the emulsion tube behind the choke. It LOOKS like it is coming from the bottom connection point of the choke butterfly where it swivels. 

Ideas???

I checked locally and the parts person could not find a compatible replacement carb. Not saying I can't find one, but not from this particular shop. I want to beat the carb rather than give in and replace it.


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## ColoradoDoug (Feb 18, 2016)

You can see the bowl is wet and dripping, but it is coming from the carb throat and running down and around the bowl. The black on the bowl is spray paint from the prior owner.










The butterfly looks dirty in this picture, but I cleaned it with carb cleaner several times and with a rag. I think it is stained. 










You can see the fuel coming out of the throat.


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## ColoradoDoug (Feb 18, 2016)

A small addition, I can start the engine and it will not drip fuel. Only when not running. I understand that the suction into the intake is probably preventing that (assumed).


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## nwcove (Mar 2, 2015)

in theory, theres only a couple things that can cause your issue.....float not floating, needle not seating. jmo


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## AL- (Oct 27, 2014)

If you are referring to the Dony Boy 73 four part video, that went quite smoothly, I used that too and had no problem. However in the second part video after he takes the float off he uses the Tecumseh tool and removes the white float needle seat, he checks this white seat and then reinserts it back into the small carb aperture without checking this aperture. If this area was pitted or had a bit of flaked varnish etc. I would think gas might be able to ooze out from in back of the white needle seat. The float needle and white seat combination however might work fine. 
I have only cleaned a couple of these, but you seem to have a small, hard to find problem. Good Luck


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## Mr Fixit (Nov 19, 2013)

I would sure like to test this carb in open air with the gas tank connected and/but the bowl off. If holding the float up by hand stops the gas coming in totally, then the float movement is interfered with by the bowl walls somehow? It's not centered or it's a bent hinge?


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## suspicionogignorance3 (Jun 12, 2014)

I would investigate a tiny sliver of debris, perhaps a piece of fuel line or even a thread., is "hiding in the inlet canal" before the needle/seat...and it moves towards the seat when gas is flowing and holds the needle from seating..I would drop the float, remove the needle/seat, remove the fuel line from the inlet, and Blow compressed air backwards from the inside seat area out thru the inlet nipple to hopefully clear and be sure only fuel enters when reassembled...??


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## alleyyooper (Sep 12, 2015)

I will repete polish that valve seat with some fine rubbing compound or silver polish. May be mill marks in there that allows a little fuel to leak past.

 Al


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## skutflut (Oct 16, 2015)

Time to cut your loses and spring for a new carb. You can keep at it with the old one, but you need a reliable one for next season jmho


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