3000 gasser pours gas out of carb

[Mtn.Mike]

My 1972 started running really rough and I noticed gas pouring out of the carb. Since it was the original carb (Holley) I changed to a Zenith thinking the Holley was worn out.
Now the Zenith does the same thing. The tractor will start but despite moving the throttle there is no power advance just gas pouring out of the carb. I have tried to set the fast idle screw but there is no change weather I turn it all the way in or all the way out.
I can change the fuel feed to gravity and the tractor runs fine but due to the hills around here I want the gas to come from the pump and not gravity.
I have done everything I can think of to fix this but now I'm asking the forum for help.

Thanks, Mike

 

[oldnslo]

Typical failure would be something stuck under the carb inlet needle (float needle) or the float is defective. You will have to remove the float bowl and investigate.

 

[ultrarunner]

Might be crude from the tank making the needle stick...

 

[LD1]

Try tapping on the side of the carb with a small hammer/wrench/whatever. See of the gas pouring out dont stop. If it does, the float/needle was stuck.

If it still pours out, Float could have a hole in it or be mis-adjusted, or seat worn out, or debris as mentioned, or just stuck so bad the tapping didnt fix it.

 

[Mtn.Mike]

This is a brand new Zenith carb so that should rule out the above problems. I hooked up the carb for gravity flow from the tank and it runs fine. What gives?

 

[ultrarunner]

I always have to set the float on a new install... maybe the float is not correctly set?

Be careful has extra fuel anywhere is a disaster waiting to happen.

 

[CCWKen]

If gravity feed works and with pump leaks, the pump is too strong. The pump should be no more than 1-2 psi. If it's adjustable, dial it down.

Why is there a pump?

 

[4570Man]

I always have to set the float on a new install... maybe the float is not correctly set? Be careful has extra fuel anywhere is a disaster waiting to happen.

No joke there. A similar problem combined with design flaw burned my Dixie chopper.

 

[Mtn.Mike]

Pump was original on the tractor. Gravity works well on level ground but when going up steep hills the gas tank is lower than the carb so no gas flows.
Another question is why does the tractor work with gravity flow and not with pump unless the pump is putting out too much pressure?

 

[4570Man]

Pump was original on the tractor. Gravity works well on level ground but when going up steep hills the gas tank is lower than the carb so no gas flows. Another question is why does the tractor work with gravity flow and not with pump unless the pump is putting out too much pressure?

It is probably flooding it.