carb leaks

The float type carburetor on my Briggs and Stratton engine leaks gas out of the throat. I replaced the needle valve and seat but apparently that wasn't the problem because it leaks just as bad as before. I notice when the engine is not running I can shut off the valve between the gas tank and the engine and drain the carb bowl of gas, then turn the valve back on and allow the bowl to refill and it won't leak at all, until I start trying to start the engine. Then it just starts leaking again. What else could be causing it to leak like this?

 

What engine are we talking about? Horizontal shaft, vertical, 5 horse, 25 horse? It continues to leak after you shut it off, unless you drain the bowl... how much? A little drip or a stream? I think maybe a bowl vent problem, depending on what you have and when it leaks.

 

Model Number: 150212
Type: 0122 E9
Code: 070612
Horizontal shaft
Not sure the horses, those specs I can't find. It's on a 3200 psi pressure washer.

It's a stream, not just a few drips. I shut the valve off between the tank and the carb. Then I empty the bowl. Then I open the valve again. It won't leak. Until I try to start it, or maybe start it and run it for a while. Then, it'll leak. And continue to leak, even after I shut off the engine.
If the carb bowl is empty of gas (because I emptied it) and then I allow gas in from the tank which fills the bowl, it won't leak. UNTIL I try starting the engine, or start the engine and run it. Then it leaks. And won't stop leaking, even if I shut off the engine. So to stop it leaking I have to shut off the supply from the tank.

 

When you installed the new needle and seat,the seat goes only one way.It has a groove side,and a smooth side.The groove side goes down and the smooth side goes up,where the needle sits on.Hope this helps.

Jerry

 

Could be that. Also, look for a dent in the side of the bowl.

 

Nope, that's not the problem. I made sure I installed the seat with the groove side down. Actually it leaked just like it does now before I changed the old needle and seat. The old needle and seat looked fine but everybody said you can't tell by looking at it so replace it anyway, so I did but it made no difference, it still has the same leak and the old needle and seat was fine like I thought.

 

I'm almost positive certain there's no dent in the side of the bowl. I don't have it in front of me right now to look specifically, but I've had the bowl off many times and I never noticed it looking as if it had any dent. How the heck would it get dented anyway?
What about possibility of a bowl vent problem as you mentioned earlier?

 

Yep, it turned out to be a bowl vent issue. I discovered there is a vent hole on the side of the carb where it mates with the air cleaner housing base. Last few times I had removed the air cleaner housing base (for different reasons) and then reinstalled it back to the carb, I had been ignorantly placing the paper gasket between them with the wrong side out (backward), and by doing that I was blocking the vent.

 

Great! Glad you got it.
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have yet to see a complete answer on the removal of the seat. in case i really want to replace the seat, how do you get that teeny rubber seat out?

 

See this: http://forum.doityourself.com/outdoo...ml#post1838363