Gas Flow not Stopping

earthfromspace

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So I know there are tons of posts on this same subject, I have read a bunch of them, gone through youtube videos on cleaning a carb. My buddy had my B&S Super Bronco Tiller for about 2 years, had left gas in it. When I finally got it back I filled up the gas tank and went out. Came home to the gas leaking out through the air filter. I had never done any carb work before so didn't know to pinch off the hose, so learning as I go. Anyway bought a carb overhaul kit, cleaned the carb good put it all back together and gas still leaking. I checked the float, didnt have liquid in it. The needle and seat was replaced, I put the seat with the grove facing into the body. float was level and made sure the seat was pushed in. it's possible the gas is not pushing the needle enough to close off the gas, not sure how to figure out if that is happening for sure. Anyway, removed and put the seat back in, the gas is obviously going into the bowl, but something is not allowing the needle to close off the flow. Not sure where to go from here, I also had changed the valve throttle, so between the kit and that it was around $26 with shipping and all. a new carb I saw for only about $58 so at some point, it might have been cheaper to simply buy a new carb, but this gives me some experience to fix things myself. I have 2 non-starting 2-cycle leaf blowers which 2-cycle I always have problems probably due to my mixing, so have had my 4-cycle blower for about 5 years now with no problem. Anyway I digress, this is all a great learning experience for me, but at this stage, maybe the float is not being pushed up enough by the gas to close off the gas flow.....any suggestions would be great.
 

ILENGINE

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The problem could be any where from a crooked seat, to a small tear in the seat area, to the seat swelled and not sealing properly, to a piece of small dirt stuck to the seat. I have had a few carbs over the years that the only way to repair was to replace the carb.
 

earthfromspace

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The problem could be any where from a crooked seat, to a small tear in the seat area, to the seat swelled and not sealing properly, to a piece of small dirt stuck to the seat. I have had a few carbs over the years that the only way to repair was to replace the carb.

thanks. I did replace the seat. the original seat was kind of stuck in there and I had to pry it out, maybe I could have caused some problems to the carb body there, but it leaked similarly before I did all all the work and is why I am thinking the bowl might not be floating enough to push the needle closed, but there is no liquid in the float. Could a float go bad without having a hole in it? Maybe due to the original seat sticking, I need to try and clean any residue that might be keeping the seat from sealing correctly?
 

Rivets

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As IL said, normally this is a needle/seat problem, but I have seen another cause. That is that the rubber gasket between the float bowl and carb body. If it is not sealing properly, it act like a needle/seat problem.
 

earthfromspace

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As IL said, normally this is a needle/seat problem, but I have seen another cause. That is that the rubber gasket between the float bowl and carb body. If it is not sealing properly, it act like a needle/seat problem.

interesting that you bring that up. I replaced that gasket, it appeared to be set correctly when I first installed it, but yesterday when I took it apart, it looked like the gasket had expanded, it no longer fit in the inner ring around the carb, but only in the outer ring, so I actually am not sure where it goes. I also don't know what it should look like for a float bowl to properly sit on the carb body, but to me it didn't look like the bowl was flush with the body, but I thought maybe thats just how it looked. Another weird problem was the main jet screw didn't seem to hand tighten fully onto the bowl it seemed to stop and needed to ratchet on the remained of the way.
 

earthfromspace

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I just ordered a new carb. :( learned much from this first time venture, but cannot stop the gas flow into carb. so I started a new venture, took apart the 2-cycle air blower, carb and gas prime bulb, seems a little simiplier, havent ventured far yet, just took it off the unit, but not apart.
 
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I just ordered a new carb. :( learned much from this first time venture, but cannot stop the gas flow into carb. so I started a new venture, took apart the 2-cycle air blower, carb and gas prime bulb, seems a little simiplier, havent ventured far yet, just took it off the unit, but not apart.

had that problem with my previous walk behind bunton. temporary fix may be a fuel shut off valve.
 

earthfromspace

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replaced the carb and all is good. starts up, no more unwanted gas flow. I have a feeling the old bowl might not be seating properly on the old one, but oh well. I'll test the old one out with some water or something.

in any case, I took the float bowl off the new carb to take a look and looks like they changed some things. rubber tipped needle, no more rubber seat. almost had a problem cus needle came off and I couldn't figure out how to put it back on because with new carb, the plastic tip goes on top as the new needle has a wire that holds it onto the float. on the older model, the the tab goes on the bottom because it pushes the needle up, where on the new one the tab goes on the top.

learned some things on my first small engine carb overhaul, now onto the 2-cycle blowers that have stopped working.
 

gregjo1948

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If you have an electric fuel solenoid, it could be faulty. gregjo1948
 

earthfromspace

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If you have an electric fuel solenoid, it could be faulty. gregjo1948

of course I didn't know what that was so looked it up a video on someone testing and replacing one.....but no, I did not have one of those. thx for the added info.
 
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